Patent Application
20070273237
An embodiment and its modifications according to the present invention will now be described with reference to the accompanying drawings, in which like reference numerals indicate like parts, members or elements throughout the specification unless otherwise indicated.
A tandem alternator 1 shown in
The alternator 1 may further have a pulley 9 on a front side of the alternator 1, a front frame 7 with which front portions of the sections 21 and 31 are covered, and a rear frame 8 with which rear portions of the sections 21 and 31 are covered. The pulley 9 receives a rotational force from an engine (not shown) through a belt (not shown) wound around the pulley 9.
The rotor section 21 has a first rotor 3 and a second rotor 4 disposed tandem around the shaft 2 so as to align the pulley 9, the first rotor 3 and the second rotor 4 in that order along an axial direction of the alternator 1. Each rotor is formed substantially in a columnar shape. The stator section 31 has a first stator 5 disposed along a circumferential surface of the first rotor 3 and a second stator 6 disposed along a circumferential surface of the second rotor 4. Each stator is formed substantially in a cylindrical shape.
Each of the rotors 3 and 4 has a field core 10 fixed to the shaft 2, a field coil 11 wound around the core 10 through a bobbin (not shown), and a cooling fan 12 fixed to the core 10. Each core 10 is formed of a pair of Lundell type pole cores facing each other along the axial direction. Each pole core has a plurality of (e.g., eight) nail-shaped magnetic poles 10a aligned along a circumferential direction of the rotor. The poles 10a of one pole core and the poles 10a of the other pole core are alternately disposed along the circumferential direction.
Each coil 11 is electrically connected with a pair of slip rings (not shown) wound around the shaft 2 on its rear side. Each slip ring is rotatably in contact with a brush element of a brush apparatus such that each coil 11 receives a field current from an on-vehicle battery (not shown) through the brush apparatus and the slip rings.
Each fan 12 is fixed to an end surface of the core 10 in the axial direction by welding or the like. The fan 12 of the first rotor 3 is disposed on the front side of the rotor 3, and the fan 12 of the second rotor 4 is disposed on the rear side of the rotor 4.
Each of the stators 5 and 6 has an armature core 13 substantially formed in a cylindrical shape and two three-phase armature wirings 14 wound around the core 13. Each three-phase armature wiring 14 has three phase wirings 14P (see
As shown in
The number of slots 13a in each core 10 is determined as follows. The slots 13a receiving one of two armature wirings 14 are differentiated from the slots 13a receiving the other armature wiring 14. Because the number of magnetic poles in each core 10 is sixteen, each of three phase wirings 14P of the wiring 14 is received in sixteen slots 13a. Therefore, the total number of slots 13a in each core 13 is set at 96 (=16×3×2) for six phase wirings 14P of two armature wirings 14.
The front frame 7 is disposed on the side of the pulley 9, and the rotor 3 and stator 5 are covered with the frame 7. The frame 7 rotatably holds a front portion of the shaft 2 through a set of bearings 15. The rear frame 8 is disposed on the opposite side of the pulley 9, and the rotor 4 and stator 6 are covered with the frame 8. The frame 8 rotatably holds a rear portion of the shaft 2 through another set of bearings 15.
With this arrangement of the alternator 1, when a rotational force of an engine (not shown) of a vehicle is transmitted to the pulley 9 through a belt (not shown), the shaft 2 is rotated with the pulley 9, and each of the rotors 3 and 4 are rotated with the shaft 2. Further, the field coil 11 of each rotor receives a field current from a battery (not shown) of the vehicle though a brush apparatus. The field current is changed to an alternating current by the slip rings. Therefore, each rotor having the magnetic poles generates a magnetic flux rotated around a rotational axis of the shaft 2, and each of the stators 5 and 6 induces an electric current in response to the rotated magnetic flux of the corresponding rotor. A voltage of this induced current is adjusted in a voltage controller (not shown) and the induced current is changed to a direct current in a rectifier (not shown). Therefore, the alternator 1 can generates an electric power. The induced current is transmitted to current consumers (not shown) and the battery.
Next, a winding structure of each armature winding 14 is described in detail with reference to
Each armature winding 14 is obtained by connecting three phase wirings 14P with one another in Y-connection. Each phase wiring 14P is obtained by serially connecting six continuous conductor members 16 shown in
For convenience of explanation, the slots 13a are identified by slot numbers S1 to S96 and are called S1-numbered slot, S2-numbered slot, - - - , and S96-numbered slot. The slots 13a are numbered so as to be counterclockwise arranged in the order of increasing the slot number. Each slot 13a has six accommodation regions aligned along a radial direction of the core 13 to receive six straight portions 160 of six members 16 of one phase wiring 14P in the accommodation regions. Two accommodation regions of each slot 13a, respectively, disposed on both ends of the slot in the radial direction are called an innermost region of a first address and an outermost region of a six address. Further, the other accommodation regions of each slot 13a are called a first middle region of a second address, a second middle region of a third address, a third middle region of a fourth address, and a fourth middle region of a fifth address along a direction from the inner circumferential side to the outer circumferential side of the cylindrical shaped core 13. The six members 16 are called a first wiring 16a, a second wiring 16b, a third wiring 16c, a fourth wiring 16d, a fifth wiring 16e and a sixth wiring 16f. The members 16 are serially connected in the order of the wirings 16e, 16c, 16a, 16b, 16d and 16f, as described later in detail.
Each member 16 of the phase wiring 14P is received in a first slot group composed of the S1-numbered slot 13a, the S7-numbered slot 13a, - - - , the S85-numbered slot 13a and the S91-numbered slot 13a disposed every six slots so as to go around the core 13 along the circumferential direction. Further, two accommodation regions of two predetermined addresses are alternately selected for each slot 13a to receive each member 16 in the selected accommodation region, so that the member 16 is wound around the core 13 in wave winding.
More specifically, the first wiring 16a is received in one of the innermost and first middle regions of each slot 13a while changing the address of the accommodation region every slot. Both end portions of the first wiring 16a are, respectively, drawn out from the innermost region of the S1-numbered slot 13a and the first middle region of the S91-numbered slot 13a on a specified side of the core 13. In case of the stator 5, the specified side denotes the front side (i.e., the side of the pulley 9). In contrast, in case of the stator 6, the specified side denotes the rear side (i.e., the opposite side of the pulley 9). The third wiring 16c is received in either the second middle region or the third middle region of each slot 13a while changing the address of the accommodation region every slot. Both end portions of the third wiring 16 care, respectively, drawn out from the second middle region of the S1-numbered slot 13a and the third middle region of the S91-numbered slot 13a on the specified side. The fifth wiring 16e is received in either the fourth middle region or the outermost region of each slot 13a while changing the address of the accommodation region every slot. Both end portions of the fifth wiring 16e are, respectively, drawn out from the fourth middle region of the S1-numbered slot 13a and the outermost region of the S91-numbered slot 13a on the specified side.
Further, the second wiring 16b is received in one of the innermost and first middle regions of each slot 13a while changing the address of the accommodation region every slot. Both end portions of the second wiring 16b are, respectively, drawn out from innermost region of the S7-numbered slot 13a and the first middle region of the S1-numbered slot 13a on the specified side. The fourth wiring 16d is received in either the second middle region or the third middle region of each slot 13a while changing the address of the accommodation region every slot. Both end portions of the fourth wiring 16d are, respectively, drawn out from the second middle region of the S7-numbered slot 13a and the third middle region of the S1-numbered slot 13a on the specified side. The sixth wiring 16f is received in one of the fourth middle and outermost regions of each slot 13a while changing the address of the accommodation region every slot. Both end portions of the sixth wiring 16f are, respectively, drawn out from the fourth middle region of the S7-numbered slot 13a and the outermost region of the S1-numbered slot 13a on the specified side.
Therefore, the first and second wirings 16a and 16b are alternately received in the innermost and first middle regions of the slots 13a, the third and fourth wirings 16c and 16d are alternately received in the second middle and third middle regions of the slots 13a, and the fifth and sixth wirings 16e and 16f are alternately received in the fourth middle and outermost regions of the slots 13a.
The end portion of the sixth wiring 16f drawn out from the fourth middle region of the S7-numbered slot 13a is connected with the end portion of the fourth wiring 16d drawn out from the third middle region of the S1-numbered slot 13a to form a connection 14f on the specific side. The end portions of the fourth wiring 16d drawn out from the second middle region of the S7-numbered slot 13a is connected with the end portion of the second wiring 16b drawn out from the first middle region of the S1-numbered slot 13a to form a connection 14g on the specific side. Therefore, the wirings 16b, 16d and 16f are serially connected with one another to form another wave winding 16B of three turns.
Further, the end portion of the first wiring 16a drawn out from the innermost region of the S1-numbered slot 13a is connected with the end portion of the second wiring 16b drawn out from the innermost region of the S7-numbered slot 13a to form a return portion 14a from these end portions on the specific side. Therefore, the wave windings 16A and 16B are connected with each other so as to form a first phase wiring 14P of six turns. The end portion of the fifth wiring 16e drawn out from the outermost region of the S91-numbered slot 13a forms an end portion 14b1 of the first phase wiring 14P, and the end portion of the sixth wiring 16f drawn out from the outermost region of the S1-numbered slot 13a forms an end portion 14c1 of the first phase wiring 14P. The end portion 14b1 is used as an output leading line, and the end portion 14c1 is used as a neutral point line.
In the same manner, a second phase wiring 14P of six turns is wound around the core 13 by receiving each of other six wirings 16a to 16f in a second slot group composed of the S2-numbered slot 13a, the S8-numbered slot 13a, - - - , the S86-numbered slot 13a and the S92-numbered slot 13a disposed every six slots and serially connecting the wirings 16a to 16f with one another. The second phase wiring 14P has an output leading line 14b2 drawn out from the outermost region of the S92-numbered slot 13a, a neutral point line 14c2 drawn out from the outermost region of the S2-numbered slot 13a, and another return line drawn out from the innermost regions of the S2 and S8-numbered slots 13a.
A third phase wiring 14P of six turns is wound around the core 13 by receiving each of other six wirings 16a to 16f in a third slot group composed of the S3-numbered slot 13a, the S9-numbered slot 13a, - - - , the S87-numbered slot 13a and the S93-numbered slot 13a disposed every six slots and serially connecting the wirings 16a to 16f with one another. The third phase wiring 14P has an output leading line 14b3 drawn out from the outermost region of the S93-numbered slot 13a, a neutral point line 14c3 drawn out from the outermost region of the S3-numbered slot 13a, and another return line drawn out from the innermost regions of the S3 and S9-numbered slots 13a.
A fourth phase wiring 14P of six turns is wound around the core 13 by receiving each of other six wirings 16a to 16f in a fourth slot group composed of the S4-numbered slot 13a, the S10-numbered slot 13a, - - - , the S88-numbered slot 13a and the S94-numbered slot 13a disposed every six slots and serially connecting the wirings 16a to 16f with one another. The fourth phase wiring 14P has an output leading line 14b4 drawn out from the outermost region of the S94-numbered slot 13a, a neutral point line 14c4 drawn out from the outermost region of the S4-numbered slot 13a, and another return line drawn out from the innermost regions of the S4 and S10-numbered slots 13a.
A fifth phase wiring 14P of six turns is wound around the core 13 by receiving each of other six wirings 16a to 16f in a fifth slot group composed of the S5-numbered slot 13a, the S11-numbered slot 13a, - - - , the S89-numbered slot 13a and the S95-numbered slot 13a disposed every six slots and serially connecting the wirings 16a to 16f with one another. The fifth phase wiring 14P has an output leading line 14b5 drawn out from the outermost region of the S95-numbered slot 13a, a neutral point line 14c5 drawn out from the outermost region of the S5-numbered slot 13a, and another return line drawn out from the innermost regions of the S5 and S11-numbered slots 13a.
A sixth phase wiring 14P of six turns is wound around the core 13 by receiving each of other six wirings 16a to 16f in a sixth slot group composed of the S6-numbered slot 13a, the S12-numbered slot 13a, - - - , the S90-numbered slot 13a and the S96-numbered slot 13a disposed every six slots and serially connecting the wirings 16a to 16f with one another. The sixth phase wiring 14P has an output leading line 14b6 drawn out from the outermost region of the S96-numbered slot 13a, a neutral point line 14c6 drawn out from the outermost region of the S6-numbered slot 13a, and another return line drawn out from the innermost regions of the S6 and S12-numbered slots 13a.
The neutral point lines 14c1, 14c3 and 14c5 of the first, third and fifth phase wirings 14P are connected with one another in Y-connection, so that the core 13 is wound with a first three-phase armature wiring 14 formed of the first, third and fifth phase wirings 14P. The neutral point lines 14c2, 14c4 and 14c6 of the second, fourth and sixth phase wirings 14P are connected with one another in Y-connection, so that the core 13 is wound with a second three-phase armature wiring 14 formed of the second, fourth and sixth phase wirings 14P. The output leading lines 14b1 to 14b6 of the six phase wirings 14P are connected with a regulator (not shown).
The armature wirings 14 are wound around each of the cores 13 of the stators 5 and 6. As shown in
More specifically, the turn portions 161 in each group of coil ends are disposed so as to form three layers aligned along the radial direction, and the turn portions 161 in each layer are regularly disposed along the circumferential direction such that one turn portion 161 is placed every slot. The innermost layer is formed of the turn portions 161 of the first and second wirings 16a and 16b alternately received in the innermost and first middle regions of the slots 13a. The middle layer is formed of the turn portions 161 of the third and fourth wirings 16c and 16d alternately received in the second middle and third middle regions of the slots 13a. The outermost layer is formed of the turn portions 161 of the fifth and sixth wirings 16c and 16d alternately received in the fourth middle and outermost regions of the slots 13a.
The connections 14d to 14g and return portions 14a of the armature wirings 14 of each stator are placed in the first group of coil ends 14A. These return portions 14a are disposed at the innermost position of the first group of coil ends 14A. The return portions 14a may be disposed to be shifted from the innermost position of the first group of coil ends 14A toward the core 10 of the corresponding rotor along the radial direction. That is, the return portions 14a drawn out from the innermost regions of first slots (S1 to S12-numbered slots) 13a may be shifted along the radial direction to be further away from the outermost regions of the first slots 13a. For example, the return portions 14a may be disposed between the cores 10 and 13 in the radial direction.
In contrast, the output leading lines 14b (14b1 to 14b6) and the neutral point lines 14c (14c1 to 14c6) are disposed at the outermost position of the first group of coil ends 14A toward the frame 7 or 8. The output leading lines 14b and the neutral point lines 14c maybe disposed to be shifted from the outermost position of the first group of coil ends 14A toward the frame 7 or 8 along the radial direction. That is, the lines 14b and 14c drawn out from the outermost regions of second slots (S91 to S96-numbered slots and S1 to S6-numbered slots) 13a may be shifted along the radial direction to be further away from the innermost regions of the second slots 13a. For example, the lines 14b and 14c maybe led outside the core 13 along the radial direction and penetrate through the frame 7 or 8 along the axial direction.
As described above, the end portions of the phase wirings 14P composed of the output leading lines 14b and the neutral point lines 14c are drawn out from the outermost regions of the second slots 13a placed furthest away from the innermost regions of the second slots along the radial direction, and the return portions 14a of the phase wirings 14P are drawn out from the innermost regions of the first slots coinciding with or placed near the second slots. Accordingly, this arrangement prevents the output leading lines 14b and the neutral point lines 14c from crossing over or overlapping with the return portions 14a along the axial direction in the first group of coil ends 14A.
Further, the connections 14e and 14g of the phase wirings 14P are formed between the first middle and second middle regions of the slots 13a along the radial direction, and the connections 14d and 14f of the phase wirings 14P are formed between the third middle and third middle regions of the slots 13a along the radial direction. Therefore, the connections 14d to 14g are disposed to be away from the innermost and outermost regions of the slots 13a from which the lines 14b and 14c and the return portions 14a are drawn out. Accordingly, this arrangement prevents the connections 14d to 14g from crossing over or overlapping with the output leading lines 14b, the neutral point lines 14c or the return portions 14a in the axial direction in the first group of coil ends 14A. In this case, the height of the first group of coil ends 14A of the armature windings 14 in the axial direction can be lowered, so that the alternator 1 can be downsized in the axial direction.
Moreover, the connections 14d and 14e of the armature windings 14 of each stator are disposed at positions different from those of the connections 14g and 14f in the circumferential direction, the connections 14d are disposed at positions different from those of the connections 14e in the radial direction, and the connections 14f are disposed at positions different from those of the connections 14g in the radial direction. Accordingly, this arrangement prevents lines including the connections 14d to 14g from crossing over or overlapping with one another in the axial direction in the first group of coil ends 14A, so that the height of the first group of coil ends 14A in the axial direction can be further lowered. Further, the conductor members 16 can be easily connected one another on the same side of the core 13 to form each phase wiring 14P.
Furthermore, the conductor members 16 of each phase wiring 14P are disposed without crossing over or overlapping with one another in the axial direction in each group of coil ends. Accordingly, as compared with the alternator disclosed in the Publication No. 2004-350381, the alternator 1 can be downsized in the axial direction.
Still further, each continuous conductor member 16 is bent and shaped in a predetermined shape pattern so as to be continuously formed without joints or seams. Accordingly, no connection in the armature winding 14 is required for each slot in the groups of coil ends 14A and 14B, so that the armature winding 14 can be easily wound around the core 13.
Still further, the alternator 1 is formed in a tandem structure having a first group of rotor 3 and stator 5 and a second group of rotor 4 and stator 6. The end portions 14b and 14c and return portions 14a of the phase wirings 14P in the stator 5 are placed on the front side of the core 13 opposite to the stator 6, and the end portions 14b and 14c and return portions 14a of the phase wirings 14P in the stator 6 are placed on the rear side of the core 13 opposite to the stator 5. Therefore, no end portions or return portions of the phase wirings 14P are disposed in the second group of coil ends 14B placed between the cores 13 of the stators 5 and 6. Accordingly, a distance between the stators 5 and 6 in the axial direction can be shortened, so that a tandem type alternator can downsized in the axial direction.
In this embodiment described above, the return portions 14a of the phase wirings 14P are drawn out from the innermost regions of the first slots 13a, while the end portions 14b and 14c of the phase wirings 14P are drawn out from the outermost regions of the second slots 13a. However, the return portions 14a of the phase wirings 14P may be drawn out from the outermost regions of the first slots 13a, and the end portions 14b and 14c of the phase wirings 14P may be drawn out from the innermost regions of the second slots 13a.
Further, six continuous conductor members 16 are, respectively, disposed in six accommodation regions of each slot 13a to be aligned in the slot along the radial direction. However, the number of accommodation regions in each slot may be set at 2n (n is an integral number equal to or larger than 2).
Moreover, three phase wirings 14P are connected with one another in Y-connection to form one armature winding 14. However, three phase wirings 14P may be connected with one another in Δ-connection to form each armature winding 14.
Furthermore, each conductor member 16 continuously formed in advance are inserted into sixteen slots. However, as shown in
Still further, this embodiment should not be construed as limiting the present invention to the alternator having a tandem structure, and the present invention can be applied for an alternator having only a single set of rotor and stator.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-145311 | May 2006 | JP | national |
