JP2017229176A - Vehicular rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vehicular rotary electric machine capable of reducing ventilation resistance in cooling air discharge windows and improving cooling capacity by specifying a positional relation among spokes and support ribs.SOLUTION: A plurality of support ribs are dispersed and arranged in a circumferential direction on a peripheral wall part of a front side housing in a state of being coupled to a bearing housing part by spokes extending in a radial direction. A plurality of cooling air suction windows are arranged side-by-side in the circumferential direction at an outside in a radial direction of the bearing housing part of a bottom of the front side housing in a state of being partitioned by the spokes. The plurality of cooling air discharge windows are arranged side-by-side in the circumferential direction on the peripheral wall part in a state of being partitioned by the support ribs. The number of the spokes is the same as the number of the support ribs. Each of the plurality of spokes is shifted by the same angle in an opposite direction to a rotation direction of a rotor with respect to the corresponding support rib out of the plurality of support ribs.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicular rotating electrical machine such as an automotive alternator, and more particularly to a vehicular rotating electrical machine having a built-in cooling fan.

  A vehicular AC generator, which is a vehicular rotating electrical machine, performs auxiliary charging of a battery while the vehicle is running and covers electric power of in-vehicle electrical components, and is demanded to be smaller, lighter and have higher output. However, downsizing the vehicle alternator leads to downsizing of the cooling fan, reducing the amount of cooling air that cools the electrical components built in the vehicle alternator and lowering the cooling capacity. .

  In view of such a situation, various techniques for improving the cooling capacity of the AC generator for a vehicle by devising the shape of the cooling air discharge window of the housing have been proposed. For example, in Patent Document 1, four support portions that support the stator are arranged on the side surface at equal intervals, and a plurality of ribs that form a plurality of cooling air discharge windows are disposed between the support portions. The plurality of ribs forming the cooling air discharge window are inclined with respect to the radial direction of the rotating shaft, and the inclination angle is large in the vicinity of the support portion used for supporting the stator, and from the support portion. It was set to be small at a distant position. By adopting such a structure, it is possible to mitigate a sudden change in the flow of the cooling air generated at the boundary between the cooling air discharge window and the support portion, and to reduce noise while maintaining the cooling capacity.

JP 2007-174774 A

  In Patent Document 1, the angle of inclination of the plurality of ribs forming the cooling air discharge window is devised to reduce the airflow resistance in the cooling air discharge window, but the support portion reduces the airflow resistance to the cooling air. There has been a problem that the cooling capacity cannot be sufficiently improved by acting so as to increase.

  The present invention has been made to solve such a problem, and the positional relationship in the rotational direction of the rotor between the spokes of the housing and the support rib is determined when the cooling air flows out of the cooling air discharge window. The object is to obtain a rotating electrical machine for a vehicle that can reduce the ventilation resistance by identifying the positional relationship between the spokes and the support ribs and reducing the ventilation resistance in the cooling air discharge window and improving the cooling capacity by finding that the ventilation resistance can be reduced. And

  A rotating electrical machine for a vehicle according to the present invention is fixed to a stator held by a front housing and a rear housing from both sides in an axial direction, and a shaft rotatably supported by the front housing and the rear housing. And a rotor arranged coaxially with the stator on the inner peripheral side of the stator and provided with a cooling fan on the front side. The front-side housing has a peripheral wall portion and a bottom portion that closes one side opening of the peripheral wall portion, and a bearing storage portion is provided at the axial center position of the bottom portion so as to be opposed to the shaft. A state in which a plurality of ribs are distributed in the circumferential direction on the peripheral wall portion in a state where the ribs are connected to the bearing housing portion by spokes extending in the radial direction, and the cooling air intake window is partitioned by the spokes A plurality of cooling air discharge windows arranged in the circumferential direction on the outer side in the radial direction of the bearing housing portion at the bottom, and arranged in the circumferential direction on the peripheral wall portion in a state of being partitioned by the support ribs. The cooling air is arranged and is sucked from the cooling air suction window and discharged from the cooling air discharge window by the rotation of the cooling fan. The number of the spokes is the same as the number of the support ribs, and each of the plurality of spokes is opposite to the rotation direction of the rotor with respect to the corresponding support rib among the plurality of support ribs. Shifted by the same angle.

  According to the present invention, the number of spokes is the same as the number of support ribs, and each of the plurality of spokes is opposite to the rotation direction of the rotor with respect to the corresponding support rib among the plurality of support ribs. The direction is shifted by the same angle. Therefore, the angle between the spokes that make up the cooling air intake window is the same angle as the angle between the supporting ribs that make up the corresponding cooling air discharge window in the cooling air discharge window. It becomes. Further, the spokes constituting the cooling air suction window are shifted by the same angle in the opposite direction to the rotation direction of the rotor with respect to the support rib constituting the corresponding cooling air discharge window in the cooling air discharge window. ing. As a result, the occurrence of a collision between the cooling air swirled in the rotational direction by the cooling fan and reaching the peripheral wall portion of the front housing and the support rib is suppressed. As a result, the ventilation resistance when the cooling air flows through the cooling air discharge window is reduced, and the cooling capacity is improved.

It is sectional drawing explaining the structure of the alternating current generator for vehicles which concerns on Embodiment 1 of this invention. It is the end elevation which looked at the alternator for vehicles concerning Embodiment 1 of this invention from the front side. It is a figure explaining the flow of the cooling wind which flows through the cooling wind discharge window in the front side housing of the alternating current generator for vehicles which concerns on Embodiment 1. FIG. It is a figure explaining the flow of the cooling wind which flows through the cooling wind discharge window in the front side housing of a comparative example. It is a figure which shows the relationship between spoke shift angle (theta) 1 in the front side housing of the alternating current generator for vehicles concerning Embodiment 1 of this invention, and the average flow velocity of the cooling air which flows out out of a cooling air discharge window. It is a figure which shows distribution of the average flow velocity of the cooling wind in the circumferential direction in the cooling wind discharge window in the front side housing of the alternating current generator for vehicles concerning Embodiment 1 of this invention. It is a figure which shows the relationship between spoke shift angle (theta) 1 in the front side housing of the alternating current generator for vehicles concerning Embodiment 2 of this invention, and the average flow velocity of the cooling air which flows out out of a cooling air discharge window. It is a figure which shows the relationship between spoke shift angle (theta) 1 in the front side housing of the alternating current generator for vehicles concerning Embodiment 3 of this invention, and the average flow velocity of the cooling air which flows out out of a cooling air discharge window.

  Hereinafter, preferred embodiments of a rotating electrical machine for a vehicle according to the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view illustrating the configuration of an automotive alternator according to Embodiment 1 of the present invention, and FIG. It is the end view seen from.

  In FIG. 1, a vehicular AC generator 1 as a vehicular rotating electrical machine includes a casing 4 composed of a front housing 2 and a rear housing 3 made of substantially bowl-shaped aluminum, and a pair of bearings 5 on the casing 4. A shaft 6 that is rotatably supported via a shaft, a pulley 7 that is fixed to an end portion of the shaft 6 that protrudes to the front side of the casing 4, and a shaft 6 that is fixed to the shaft 6 and disposed in the casing 4. A rotor 8 that rotates integrally with the rotor 8, a stator 9 that is fixed to the casing 4 so as to surround the rotor 8, and a protruding portion of the shaft 6 that protrudes to the rear side of the casing 4. A pair of slip rings 10 for supplying current, a pair of brushes 11 accommodated in the brush holder 17 and sliding on the surface of each slip ring 10, and a brush holder A voltage regulator 12 that is fixed to a heat sink 12a attached to 17 and disposed adjacent to the pair of brushes 11 and adjusts the magnitude of the AC voltage generated in the stator 9, and the AC voltage generated in the stator 9 A rectifier 13 for converting to a DC voltage, a connector 20 for exchanging signals between the voltage regulator 12 and an external device (not shown), and the rear so as to cover the voltage regulator 12, the rectifier 13 and the brush holder 17. And a protective cover 27 attached to the side housing 3.

  The rotor 8 is a Landel-type rotor, which is manufactured by winding an insulated copper wire in a cylindrical shape and concentrically, and a field winding 81 that generates magnetic flux by flowing an excitation current, and an axial center. A field iron core 82 fixed to the shaft 6 penetrating the position and covering the field winding 81 and having a magnetic pole formed by a magnetic flux generated in the field winding 81, and a blade 83a by, for example, sheet metal processing And a cooling fan 83 that is fixed to both axial end surfaces of the field core 82 by welding or the like and rotates integrally with the field core 82. The field iron core 82 is configured by, for example, alternately engaging eight claw portions. In this case, the number of poles of the rotor 8 is 16.

  The stator 9 is a cylindrical stator core 91, and a stator winding 92 that is attached to the stator core 91, and an alternating current is generated by a change in magnetic flux from the field winding 81 as the rotor 8 rotates. It is equipped with. The stator 9 has a through bolt 40 passed from the rear side to the bolt housing portion of the support portion 25 of the rear housing 3 and fastened to the female screw groove of the bolt housing portion of the support portion 25 of the front side housing 2. The stator core 91 is sandwiched between the opening ends of the front housing 2 and the rear housing 3 from both sides in the axial direction, and is disposed coaxially on the outer periphery of the rotor 8. The lead wire 92a of the stator winding 92 is drawn from the rear housing 3 and connected to the terminal 19a of the circuit board 19, and the rectifier 13 and the stator winding 92 are electrically connected.

The rectifying device 13 includes a positive-side heat sink 18p on which a plurality of positive-side rectifying elements are mounted, a negative-side heat sink 18n on which a plurality of negative-side rectifying elements are mounted, and a circuit board 19. A pair of the positive rectifier element and the negative rectifier element is connected via the circuit board 19 so as to form a diode bridge.
The front-side bearing 5 is housed in the bearing housing portion 21 of the front-side housing 2, and a screw 16 is fastened from the outside of the front-side housing 2 to a retainer 15 disposed on the inside so as to substantially cover the bearing outer ring. It is attached.

Next, the operation of the vehicular AC generator 1 configured as described above will be described.
The rotational torque of the engine (not shown) is transmitted to the shaft 6 via a belt (not shown) and the pulley 7, and the rotor 8 is rotated. At this time, a current is supplied to the field winding 81 of the rotor 8 via the brush 11 and the slip ring 10 to generate a magnetic flux. Due to this magnetic flux, N poles and S poles are alternately formed in the circumferential direction on the claw portions arranged on the outer periphery of the field core 82. Therefore, a rotating magnetic field is applied to the stator winding 92 of the stator 9, and an alternating electromotive force is generated in the stator winding 92. This AC electromotive force is supplied to the rectifier 13 via the lead wire 92a, rectified by the rectifier 13, and the magnitude thereof is adjusted by the voltage regulator 12, and is supplied to the vehicle-mounted load or the battery. .

  Further, the rotation of the rotor 8 rotates the cooling fan 83 fixed to both end surfaces of the field core 82 in the axial direction.

  On the front side, the cooling air is sucked from the cooling air suction window 22 formed at the bottom of the front housing 2, flows in the front housing 2 in the axial direction, reaches the field core 82, and then radially outwards. And is discharged to the outside from the cooling air discharge window 23 formed in the peripheral wall portion of the front housing 2. The field winding 81 is cooled by the axial flow component of the cooling air flowing through the front housing 2, and the front coil end of the stator winding 92 is cooled by the radial flow component of the cooling air. .

  On the rear side, the cooling air is sucked from a suction window 27 a formed in the protective cover 27, flows through the protective cover 27, and is sucked from a cooling air suction window 22 formed at the bottom of the rear side housing 3. It flows in the housing 3 in the axial direction, reaches the field core 82, is then bent outward in the radial direction, and is discharged to the outside from the cooling air discharge window 23 formed in the peripheral wall portion of the rear housing 3. Then, the voltage regulator 12 and the rectifier 13 are cooled by the cooling air flowing through the protective cover 27. Further, the field winding 81 is cooled by the axial flow component of the cooling air flowing in the rear housing 3, and the rear coil end of the stator winding 92 is cooled by the radial flow component of the cooling air. .

  Next, details of the front housing 2 will be described with reference to FIGS. 1 and 2.

  The front housing 2 is formed in a substantially arm shape including a substantially cylindrical peripheral wall portion and a bottom portion closing one side opening of the peripheral wall portion, and faces the rotor 8 at an axial center position O of the bottom portion. Are provided so as to project radially outward from positions facing each other across the axial center position O of the opening side edge portion of the peripheral wall portion. The stay 28 for attaching the alternator 1 to the engine block (not shown) of the vehicle, and two places in the vicinity of the root portion of each stay 28, that is, a total of four places on the opening side edge portion of the peripheral wall portion. And two support portions 25. The four support portions 25 are for holding the stator core 91 and are arranged at equal intervals in the circumferential direction on the opening side edge portion of the peripheral wall portion of the front-side housing 2, and are internally threaded on the inner peripheral surface. A bolt housing portion formed with

  Support ribs 26 are provided on the peripheral wall portion of the front housing 2 in the vicinity of each of the support portions 25. The support ribs 26 are for supporting the rotor 8, have a wide circumferential width, and are arranged at four equal intervals in the circumferential direction. Then, four cooling air discharge windows 23 are defined by the support ribs 26, and four cooling air discharge windows 23 are arranged at equal intervals in the circumferential direction on the peripheral wall portion of the front side housing 2. Specifically, a plurality of ribs 24 are provided in a portion of the peripheral wall portion of the front housing 2 between the support ribs 26 adjacent in the circumferential direction. Each of the plurality of ribs 24 has a narrower circumferential width than the support ribs 26 and is inclined in the rotational direction of the rotor 8 with respect to the radial direction. The cooling air discharge window 23a is formed between the adjacent ribs 24 and between the rib 24 and the support rib 26, and the group of cooling air discharge windows 23a between the adjacent support ribs 26 constitutes the cooling air discharge window 23. To do. In addition, the rotation direction of the rotor 8 means the rotation direction of the rotor 8 when the vehicle on which the vehicle alternator 1 is mounted travels forward.

  Four cooling air intake windows 22 are formed on the outer peripheral side of the bearing housing portion 21 at the bottom of the front housing 2 and are arranged at equal intervals in the circumferential direction. The bearing storage portions 21 are connected to the support ribs 26 via four spokes 30 that extend in the radial direction and divide between the cooling air suction windows 22 adjacent in the circumferential direction. Thereby, the rotor 8 is supported by the support rib 26 via the bearing storage portion 21 and the spoke 30. Note that the circumferential width of the spoke 30 is approximately the same as the circumferential width of the support rib 26.

  Here, the four support ribs 26 are arranged at equal intervals in the circumferential direction around the axial center position O, and in the plane orthogonal to the shaft 6, the support ribs 26 adjacent to the circumferential direction and the axial center position are arranged. An angle (hereinafter referred to as an angle between support ribs) θ3 formed by a line segment connecting O is 90 °. Further, the four spokes 30 are arranged at equal intervals in the circumferential direction around the axial center position O, and an angle formed by the spokes 30 adjacent in the circumferential direction on the plane orthogonal to the shaft 6 (hereinafter, spokes). Θ2 is 90 °. Then, the spoke 30 is shifted in the direction opposite to the rotation direction of the rotor 8 by the angle θ1 with respect to the corresponding support rib 26 around the axial center position O. Hereinafter, the angle θ1 is defined as the shift angle θ1 of the spoke 30. In the first embodiment, the shift angle θ1 of the spoke 30 is negative. That is, the spoke 30 is shifted by | θ1 | in the direction opposite to the rotation direction of the rotor 8 with respect to the corresponding support rib 26. When the shift angle θ1 is positive, the spoke 30 corresponds to the corresponding support rib. 26 means that the rotor 8 is shifted by θ1 in the rotation direction.

  In the rear housing 3, the bearing housing 21, the stay 28, the support 25, the cooling air intake window 22, the cooling air discharge window 23, and the like are formed in the same manner as the front housing 2. The description is omitted.

  Here, the effect of the shift angle θ1 of the spoke 30 will be described with reference to FIGS. FIG. 3 is a diagram for explaining the flow of cooling air flowing through the cooling air discharge window in the front housing of the vehicle alternator according to Embodiment 1, and FIG. 4 is the cooling air discharging window in the front housing of the comparative example. It is a figure explaining the flow of cooling air.

  In the front housing 2 according to the first embodiment, as shown in FIG. 3, the shift angle θ <b> 1 of the spoke 30 is negative, that is, the spoke 30 is opposite to the rotation direction of the rotor 8 with respect to the support rib 26. There is a shift. On the other hand, in the front housing 100 of the comparative example, as shown in FIG. 4, the shift angle θ1 of the spoke 30 is zero, that is, the installation positions in the circumferential direction of the spoke 30 and the support rib 26 are the same.

  The axial flow of the cooling air drawn from the cooling air intake window 22 is converted into a radial flow by the cooling fan 83. At this time, the cooling air flows radially outward by the blade 83 a while proceeding forward in the rotational direction of the rotor 8, that is, turning forward in the rotational direction of the rotor 8. Therefore, the cooling air is an inclined flow corresponding to the forward turning angle of the rotor 8 by the blade 83a, that is, a flow inclined forward in the rotational direction of the rotor 8 with respect to the radial direction of the shaft 6. And flows into the cooling air discharge window 23.

  In the front side housing 100 of the comparative example, the cooling air sucked from the region other than the front side in the rotation direction of the rotor 8 in the cooling air suction window 22 is discharged as shown by an arrow A in FIG. It flows out through the window 23. However, the cooling air sucked from the region on the front side in the rotation direction of the rotor 8 in the cooling air suction window 22 collides with the support rib 26 as indicated by an arrow B in FIG. As a result, the ventilation resistance when the cooling air sucked from the cooling air suction window 22 flows out through the cooling air discharge window 23 increases, and the cooling capacity decreases.

  In the front housing 2, since the shift angle θ <b> 1 of the spoke 30 is negative, the cooling air discharge window 23 is shifted forward in the rotational direction of the rotor 8 with respect to the cooling air intake window 22. Therefore, the cooling air sucked from the cooling air suction window 22 flows out through the cooling air discharge window 23 without colliding with the support rib 26 as indicated by an arrow A in FIG. In other words, by adjusting the shift angle θ1 of the spoke 30, the collision of the cooling air with the support rib 26 can be suppressed, and the ventilation resistance when the cooling air flows out through the cooling air discharge window 23 can be reduced. Cooling capacity can be improved.

  Here, as described above, the cooling air discharged from the cooling fan 83 becomes a flow inclined forward in the rotational direction of the rotor 8 with respect to the radial direction. To spread. Therefore, when the inter-spoke angle θ2 formed by the spokes 30 adjacent in the circumferential direction is larger than the inter-support rib angle θ3 formed by the adjacent support ribs 26 in the circumferential direction, the circumferential direction of the cooling air reaching the cooling air discharge window 23 The width diffuses in the circumferential direction and becomes wider than the circumferential width of the cooling air discharge window 23. As a result, even if the shift angle θ1 of the spoke 30 is adjusted, the overlap between the cooling air and the support ribs 26 increases, so that the ventilation resistance when the cooling air flows out of the cooling air discharge window 23 increases, and the cooling capacity Decreases.

  Further, in the case where the inter-spoke angle θ2 formed by the spokes 30 adjacent in the circumferential direction is smaller than the inter-support rib angle θ3 formed by the adjacent support ribs 26 in the circumferential direction, the circumferential direction of the cooling air reaching the cooling air discharge window 23 Even if the width is diffused in the circumferential direction, it becomes narrower than the circumferential width of the cooling air discharge window 23. As a result, the flow rate of the cooling air is insufficient with respect to the cooling air discharge window 23, and a desired cooling capacity cannot be obtained.

  In the first embodiment, since the inter-spoke angle θ2 formed by the spokes 30 adjacent in the circumferential direction is equal to the inter-support rib angle θ3 formed by the adjacent support ribs 26 in the circumferential direction, the air reaches the cooling air discharge window 23. The circumferential width of the cooling air is substantially equal to the circumferential width of the cooling air discharge window 23 even if it is diffused in the circumferential direction. As a result, by adjusting the shift angle θ <b> 1 of the spoke 30, the overlap between the cooling air and the support rib 26 can be minimized, so that the ventilation resistance when the cooling air flows out of the cooling air discharge window 23 is reduced. And cooling capacity can be improved.

  The circumferential width of the cooling air that has reached the cooling air discharge window 23 increases as the outer diameter of the peripheral wall portion of the front housing 2 increases, but the expansion of the circumferential width of the cooling air increases with the adjacent spokes 30. It is absorbed by equalizing the inter-spoke angle θ2 formed by and the inter-support rib angle θ3 formed by the adjacent support ribs 26. In other words, regardless of the outer diameter of the peripheral wall portion of the front housing 2, the spoke angle 30 between the spokes 30 is made equal to the support rib angle θ3 between the adjacent support ribs 26, and the spoke 30 shift angle. By adjusting θ1, the overlap between the cooling air and the support rib 26 can be minimized.

  Next, the measurement result of the average flow velocity of the cooling air flowing out from the cooling air discharge window 23 using the shift angle θ1 of the spoke 30 as a parameter is shown in FIG. FIG. 5 is a diagram showing the relationship between the spoke shift angle θ1 in the front housing of the automotive alternator according to Embodiment 1 of the present invention and the average flow velocity of the cooling air flowing out from the cooling air discharge window. In FIG. 5, the dotted line D1 indicates the average flow velocity when θ1 = 0 °, and the dotted line D2 indicates the average flow velocity when θ1 = 45 °. In addition, the outer diameter φ of the cooling fan 83 was 90 mm, the radius R1 of the cooling air intake window 22 was 43 mm, and the outer diameter of the peripheral wall portion of the front housing 2 was 130 mm. The radius R1 is a radius on the outer peripheral side of the cooling air intake window 22. The outer diameter R1 of the cooling fan 83 corresponds to the outer diameter of the blade 83a.

  From FIG. 5, it was found that as θ1 increases from 0 °, the average flow velocity of the cooling air flowing out from the cooling air discharge window 23 gradually increases. When θ1 decreases from 0 °, the average flow velocity of the cooling air flowing out from the cooling air discharge window 23 gradually increases. When θ1 = −15 °, the average flow velocity at θ = + 45 ° is exceeded. It was found that the maximum average flow velocity was obtained when θ1 = −35 °, and thereafter the average flow velocity was decreased. When θ1 = −45 °, the average flow velocity was obtained when θ1 = + 45 °. As described above, when θ1 is set in the range of −45 ° <θ1 <−15 °, the average flow velocity of the cooling air increases, and in particular, cooling is performed by setting the range of −40 ° <θ1 <−27 °. It was confirmed that the average wind velocity increased further.

  Note that the same results as in FIG. 5 were obtained when the number of rotations of the rotor 8 was changed and also when the numbers of the support ribs 26 and the spokes 30 were changed. The radius on the inner peripheral side of the cooling air intake window 22 is related to the intake flow rate of the cooling air and does not affect the turning angle of the cooling fan 83.

  Here, in the range of −45 ° <θ1 <−15 °, the amount of air colliding with the support ribs 26 of the cooling air discharged from the cooling fan 83 decreases, and the cooling air flows when it flows out of the cooling air discharge window 23. It is presumed that the draft resistance decreased and the average flow velocity increased.

  Therefore, in the first embodiment, from the viewpoint of reducing the ventilation resistance when the cooling air flows out of the cooling air discharge window 23 and improving the cooling capacity, the adjacent support rib and the inter-spoke angle θ2 formed by the adjacent spokes 30 are provided. 26, the angle θ3 between the supporting ribs is made equal, and the shift angle θ1 of the spoke 30 may be set in a range of −45 ° <θ1 <−15 °, and in a range of −40 ° <θ1 <−27 °. It is more preferable to set. In particular, if the shift angle θ1 of the spoke 30 is set to −35 °, the ventilation resistance when the cooling air flows out of the cooling air discharge window 23 is minimized, and the cooling capacity can be improved most.

  Next, the result of measuring the average flow velocity of the cooling air in the cooling air discharge windows 23 a arranged in the circumferential direction in the cooling air discharge window 23 is shown in FIG. 6. FIG. 6 is a diagram showing the distribution of the average flow velocity of the cooling air in the circumferential direction in the cooling air discharge window in the front housing of the vehicle alternator according to Embodiment 1 of the present invention. In FIG. 6, the horizontal axis indicates the circumferential position in the cooling air discharge window 23, the vertical axis indicates the average flow velocity of the cooling air, the solid line indicates the average flow velocity when θ1 = −35 °, and the dotted line Indicates the average flow velocity when θ1 = 0 °. The position A on the horizontal axis is the position of the cooling air discharge window portion 23a formed between the support rib 26 and the rib 24 on the rear side in the rotation direction of the rotor 8 in the cooling air discharge window 23. C is the position of the cooling air discharge window 23a formed between the support rib 26 and the rib 24 in the rotation direction of the rotor 8 in the cooling air discharge window 23, and the position B is the cooling air discharge. This is the position of the cooling air discharge window portion 23 a formed between the adjacent ribs 24 at a substantially intermediate position between the position A and the position C in the window 23. In addition, the outer diameter of the cooling fan 83 was 90 mm, the radius R1 of the cooling air intake window 22 was 43 mm, and the outer diameter of the peripheral wall portion of the front housing 2 was 130 mm.

From FIG. 6, when the shift angle θ1 of the spoke 30 is set to −35 °, the average flow velocity of the cooling air is increased and fluctuated as compared with the case where the shift angle θ1 of the spoke 30 is set to 0 °. It was confirmed that the air was distributed in the circumferential direction in the cooling air discharge window 23 in a small state.
This is because the shift angle θ1 of the spoke 30 is set to −35 °, so that the cooling air discharged from the cooling fan 83 does not collide with the support rib 26, and almost the entire area in the circumferential direction of the cooling air discharge window 23 is covered. It is assumed that it was caused by being leaked through.
Thus, if the shift angle θ1 of the spoke 30 is set to −35 °, the cooling capacity can be improved and the flow velocity fluctuation in the circumferential direction can be reduced.

  Here, the circumferential width of the cooling air discharge window 23 a in the cooling air discharge window 23 was constant, but the cooling air discharge window 23 a in the region from the position B to the position C in the cooling air discharge window 23. May be wider than the circumferential width of the cooling air discharge window portion 23a in the region on the position A side in the cooling air discharge window 23. In this case, the average flow velocity in the region from the position B to the position C in the cooling air discharge window 23 is further increased, and the cooling capacity can be improved. Further, the circumferential width of the cooling air discharge window portion 23a in the region from the position B to the position C in the cooling air discharge window 23 is set to the width of the cooling air discharge window portion 23a in the region on the position A side in the cooling air discharge window 23. It may be narrower than the circumferential width. In this case, the distribution of the average flow velocity in the cooling air discharge window 23 becomes uniform, and noise can be reduced.

  In the first embodiment, the case where the number of the support ribs 26 and the spokes 30 is four has been described. However, the number of the support ribs 26 is equal to the number of the spokes 30 and the spokes formed by the adjacent spokes 30 are the same. The number of the support ribs 26 and the spokes 30 is not limited to four as long as the interval angle θ2 and the support rib angle θ3 formed by the adjacent support ribs 26 are equal. Good.

  Further, in the first embodiment, the support ribs 26 and the spokes 30 are arranged at an equiangular pitch around the axial center position O. However, the number of the support ribs 26 and the number of the spokes 30 are equal, and the cooling air intake window. The angle θ2 between the spokes formed by the spokes 30 that divide 22 is equal to the angle θ3 between the support ribs formed by the support ribs 26 that divide the cooling air discharge window 23 through which the cooling air drawn from the cooling air intake window 22 flows out. For example, the support ribs 26 and the spokes 30 may not be arranged at an equiangular pitch around the axial center position O. That is, the number of the support ribs 26 and the number of the spokes 30 are equal, and each of the plurality of spokes 30 arranged in the circumferential direction corresponds to one of the plurality of support ribs 26 arranged in the circumferential direction. It is only necessary to shift the support rib 26 by the same angle in the direction opposite to the rotation direction of the rotor 8.

  In the first embodiment, the rear housing 3 is formed in the same manner as the front housing 2. However, the protective cover 27 is attached to the rear housing 3 so as to cover the voltage regulator 12, the rectifier 13 and the brush holder 17. As a result, the suction side of the cooling fan 83 on the rear side is closed compared to the suction side of the cooling fan 83 on the front side, and the swirl angle of the cooling air by the cooling fan 83 is reduced. Therefore, it is desirable to increase the cooling air flow velocity by setting the shift angle θ1 of the rear-side spoke 30 to be smaller than that of the front side.

Embodiment 2. FIG.
The second embodiment is configured in the same manner as in the first embodiment except that the cooling air suction window 22 is formed with a radius R1 larger than 43 mm.

  The cooling air flows outward in the radial direction while traveling forward in the rotational direction of the rotor 8 by the blade 83a. Then, the amount of forward movement of the cooling air by the blade 83a in the rotational direction of the rotor 8, that is, the turning angle varies depending on the radius R1 of the cooling air intake window 22. And if radius R1 becomes large, since the radial direction length which passes braid | blade 83a of cooling air will become short and a turning angle will become small, the shift to the back of the rotation direction of the rotor 8 with respect to the support rib 26 of the spoke 30 will be carried out. It is necessary to reduce the amount to suppress the collision of the cooling air with the support ribs 26.

  Here, FIG. 7 shows the result of measuring the relationship between the shift angle θ1 and the average flow velocity of the cooling air in the cooling air discharge window 23 using the radius of the cooling air intake window 22 as a parameter. FIG. 7 is a diagram showing the relationship between the spoke shift angle θ1 in the front housing of the vehicle alternator according to Embodiment 2 of the present invention and the average flow velocity of the cooling air flowing out from the cooling air discharge window. In FIG. 7, the alternate long and short dash line indicates the average flow velocity when R1 = 43 mm, the dotted line indicates the average flow velocity when R1 = 45 mm, and the solid line indicates the average flow velocity when R1 = 47 mm. D2 represents the average flow velocity when R1 = 43 mm and the shift angle θ1 = 45 °. The outer diameter φ of the cooling fan 83 is 90 mm, and the outer diameter of the peripheral wall portion of the front housing 2 is 130 mm.

  FIG. 7 shows that when R1 is 43 mm and 45 mm, the average flow velocity of the cooling air flowing out from the cooling air discharge window 23 gradually decreases as θ1 increases from −30 °. Further, when R1 is 47 mm and θ1 increases from −30 °, the average flow velocity of the cooling air flowing out from the cooling air discharge window 23 is substantially constant until θ1 is −28 °, and when θ1 exceeds −28 °. It was found that it gradually decreased. It was also found that the average flow velocity was increased in the order of R1 of 43 mm, 45 mm, and 47 mm in the range of θ1 from −28 ° to −10 °. When R1 was 43 mm, an average flow velocity equivalent to D2 was obtained when θ1 = −15 °. When R1 is 45 mm, an average flow velocity equivalent to D2 is obtained when θ1 = −12.4 °, and when R1 is 47 mm, an average flow velocity equivalent to D2 is obtained when θ1 = −10.6 °. It became. This is presumably because when the radius R1 of the cooling air intake window 22 is increased, the time during which the cooling air is swirled within the blade 83a of the cooling fan 83 is shortened, and the swirling angle of the cooling air is reduced. .

  Thus, it can be seen that when R1 is increased from 43 mm to 45 mm, the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained can be increased by the angle a. Similarly, it can be seen that when R1 is increased from 43 mm to 47 mm, the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained can be increased by an angle b. From the measurement results, a = 2.6 ° and b = 4.4 °.

Here, when t = R1-43, when R1 = 45 mm, t = 2, and the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained is substantially equal to the numerical value of the angle. Further, when R1 = 47 mm, t = 4, and the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained is substantially equal to the numerical value of the angle to be expanded.
In addition, when R1 is larger than 43 mm, the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained is enlarged by about t °, but the lower limit of θ1 at which an average flow velocity equivalent to D2 is obtained is also enlarged by about t °. To do.

  Therefore, in the second embodiment, when t = R1-43, the shift angle θ1 of the spoke 30 is set in the range of −45 ° + t ° <θ1 <−15 ° + t °, thereby supporting the cooling air. Collision with the ribs 26 is suppressed, and the average flow velocity of the cooling air can be increased. In particular, by setting the range of −40 ° + t ° <θ1 <−27 ° + t °, the collision of the cooling air with the support ribs 26 can be further suppressed, and the average flow velocity of the cooling air can be further increased.

  When the radius R1 of the cooling air intake window 22 exceeds the radius φ / 2 of the cooling fan 83, the radial length of the cooling air passing through the blade 83a becomes constant, so φ / 2 ≧ R1> 43 (mm ), The shift angle θ1 of the spoke 30 may be set.

  Further, in a region where the radius R1 is smaller than 43 mm, there is little cooling air passing through the blade 83a. As a result, the radial length of the cooling air passing through the blade 83a does not change, and the turning angle is constant. That is, in a region where the radius R1 is smaller than 43 mm, the shift angle θ1 of the spoke 30 may be set in a setting range when the radius R1 is 43 mm, that is, a range of −45 ° <θ1 <−15 °. Further, since the cooling air intake window 22 is formed on the outer peripheral side of the bearing storage portion 21, the radius R1 is larger than the radius of the bearing storage portion 21, but it can be set in consideration of the cooling air intake flow rate. Good.

Embodiment 3 FIG.
The third embodiment is configured in the same manner as in the first embodiment except that a cooling fan 83 having an outer diameter φ different from 90 mm is used.

  The cooling air flows outward in the radial direction while traveling forward in the rotational direction of the rotor 8 by the blade 83a. The amount of cooling air that is moved forward by the blade 83 a in the rotational direction of the rotor 8, that is, the turning angle, varies depending on the outer diameter φ of the cooling fan 83. When the outer diameter φ of the cooling fan 83 is increased, the radial length of the cooling air passing through the blade 83a is increased, and the turning angle is increased. Therefore, the rotation direction of the rotor 8 with respect to the support rib 26 of the spoke 30 is increased. Therefore, it is necessary to suppress the collision of the cooling air with the support ribs 26. On the other hand, when the outer diameter φ of the cooling fan 83 is reduced, the radial length of the cooling air passing through the blade 83a is shortened and the turning angle is reduced. Therefore, the rotation direction of the rotor 8 with respect to the support rib 26 of the spoke 30 It is necessary to reduce the rearward shift amount to suppress the collision of the cooling air with the support ribs 26.

  Here, the result of measuring the relationship between the shift angle θ1 and the average flow velocity of the cooling air in the cooling air discharge window 23 using the outer diameter φ of the cooling fan 83 as a parameter is shown in FIG. FIG. 8 is a diagram showing the relationship between the spoke shift angle θ1 in the front housing of the automotive alternator according to Embodiment 3 of the present invention and the average flow velocity of the cooling air flowing out from the cooling air discharge window. In FIG. 8, the alternate long and short dash line indicates the average flow velocity when φ = 90 mm, the dotted line indicates the average flow velocity when φ = 88 mm, and the solid line indicates the average flow velocity when φ = 86 mm. D2 represents the average flow velocity when R1 = 43 mm and the shift angle θ1 = 45 °. The radius R1 of the cooling air intake window 22 is 43 mm, and the outer diameter of the peripheral wall portion of the front housing 2 is 130 mm.

  FIG. 8 shows that when φ is 90 mm and 88 mm, the average flow velocity of the cooling air flowing out from the cooling air discharge window 23 gradually decreases as θ1 increases from −30 °. When φ1 is 86 mm and θ1 increases from −30 °, the average flow velocity of the cooling air flowing out from the cooling air discharge window 23 is substantially constant until θ1 is −25 °, and when θ1 exceeds −25 °. It was found that it gradually decreased. Further, it was found that in the range of θ1 from −28 ° to −10 °, the average flow velocity increases in the order of φ of 90 mm, 88 mm, and 86 mm. When φ was 90 mm, an average flow velocity equivalent to D2 was obtained when θ1 = −15 °. When φ is 88 mm, the average flow velocity is equal to D2 when θ1 = 1−12.4 °, and when φ1 is 86 mm, the average flow velocity is equal to D2 when θ1 = −10.4 °. It became. This is because when the outer diameter of the blade 83a is reduced, the distance that the cooling air drawn from the cooling air intake window 22 passes through the blade 83a of the cooling fan 83 is shortened, and the turning angle of the cooling air is reduced. It is inferred.

  Thus, when φ is reduced from 90 mm to 88 mm, it can be seen that the upper limit of θ1 at which an average flow velocity equivalent to D2 can be obtained can be increased by an angle c. Similarly, when φ is reduced from 90 mm to 86 mm, it can be seen that the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained can be increased by an angle d. From the measurement results, c = 2.6 ° and d = 4.6 °.

Here, when D3 = 90−φ, when φ = 88 mm, D3 = 2, and the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained substantially matches the numerical value of the angle. In addition, when φ = 86 mm, D3 = 4, and the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained substantially matches the numerical value of the angle.
When φ is smaller than 90 mm, the upper limit of θ1 at which an average flow velocity equivalent to D2 is obtained is enlarged by about D3 °, but the lower limit of θ1 at which an average flow velocity equivalent to D2 is obtained is also enlarged by about D3 °. To do.

  Therefore, in the third embodiment, when D3 = 90−φ (where φ <90), the shift angle θ1 of the spoke 30 is set in a range of −45 ° + D3 ° <θ1 <−15 ° + D3 °. Thus, the average flow velocity of the cooling air can be increased. In particular, the average flow velocity of the cooling air can be further increased by setting the range of −40 ° + D3 ° <θ1 <−27 ° + D3 °.

  Here, in the third embodiment, the case where the radius R1 of the cooling air suction window 22 is 43 mm is described, but the case where the radius R1 of the cooling air suction window 22 is changed will be considered.

  First, in the region where the radius R1 is smaller than 43 mm, as described in the second embodiment, there is little cooling air passing through the blade 83a, and as a result, the radial length of the cooling air passing through the blade 83a remains unchanged. The turning angle is constant. That is, in the region where the radius R1 is smaller than 43 mm, the shift angle θ1 of the spoke 30 is set to a setting range when the radius R1 is 43 mm, that is, a range of −45 ° + D3 ° <θ1 <−15 ° + D3 °. Thus, the average flow velocity of the cooling air can be increased. In particular, the average flow velocity of the cooling air can be further increased by setting in the range of −40 ° + D3 ° <θ1 <−27 ° + D3 °.

  Next, in the region where the radius R1 is larger than 43 mm, as described in the second embodiment, both the upper limit and the lower limit of θ1 at which an average flow velocity equivalent to D2 is obtained are enlarged by approximately (R1-43) °. That is, in the region where the radius R1 is larger than 43 mm, the shift angle θ1 of the spoke 30 is set in a range of −45 ° + (R1−43 + D3) ° <θ1 <−15 ° + (R1−43 + D3) °. The average flow rate of the cooling air can be increased. In particular, the average flow velocity of the cooling air can be further increased by setting in the range of −40 ° + (R1-43 + D3) ° <θ1 <−27 ° +) R1-43 + D3) °.

  In each of the above-described embodiments, the vehicle alternator has been described. However, the present invention can be applied to a vehicular rotating electrical machine such as a vehicular AC generator motor or a vehicular AC motor. Play.

  2 Front housing, 3 Rear housing, 6 Shaft, 8 Rotor, 9 Stator, 21 Bearing housing, 22 Cooling air intake window, 23 Cooling air discharge window, 26 Support rib, 30 Spoke, 83 Cooling fan, θ1 Shift angle, θ2 angle between spokes, θ3 angle between support ribs.

Claims (5)

A stator held by the front housing and the rear housing from both sides in the axial direction;
A rotor fixed to a shaft rotatably supported by the front housing and the rear housing, arranged on the inner peripheral side of the stator and coaxially with the stator, and provided with a cooling fan on the front side; With
The front-side housing has a peripheral wall portion and a bottom portion that closes one side opening of the peripheral wall portion, and a bearing storage portion is provided at the axial center position of the bottom portion so as to be opposed to the shaft. A state in which a plurality of ribs are distributed in the circumferential direction on the peripheral wall portion in a state where the ribs are connected to the bearing housing portion by spokes extending in the radial direction, and the cooling air intake window is partitioned by the spokes A plurality of cooling air discharge windows arranged in the circumferential direction on the outer side in the radial direction of the bearing housing portion at the bottom, and arranged in the circumferential direction on the peripheral wall portion in a state of being partitioned by the support ribs. Arranged,
In the rotating electrical machine in which the cooling air is sucked from the cooling air suction window by the rotation of the cooling fan and discharged from the cooling air discharge window,
The number of spokes is the same as the number of support ribs,
A vehicular rotating electrical machine in which each of the plurality of spokes is shifted by the same angle in a direction opposite to the rotation direction of the rotor with respect to the corresponding support rib among the plurality of support ribs.   When the cooling air suction window has a radius of 43 mm or less and the cooling fan has an outer diameter of φmm, the shift angle θ1 of the adjacent spokes with respect to the adjacent support ribs in the same arrangement order is the rotation direction of the rotor 2. The rotating electrical machine for a vehicle according to claim 1, wherein −45 ° + (90−φ) ° <θ1 <−15 ° + (90−φ) °, where φ <90.   3. The rotating electrical machine for a vehicle according to claim 2, wherein the spoke shift angle θ1 is −40 ° + (90−φ) ° <θ1 <−27 ° + (90−φ) °.   When the radius R1 of the cooling air intake window is larger than 43 mm and the outer diameter of the cooling fan is (90-D3) mm, the shift angle θ1 of the adjacent spokes relative to the adjacent support ribs in the same arrangement order is The rotating electrical machine for a vehicle according to claim 1, wherein -45 ° + (R1-43 + D3) ° <θ1 <-15 ° + (R1-43 + D3) ° when the rotation direction of the rotor is a positive direction.   The rotating electrical machine for a vehicle according to claim 4, wherein the spoke shift angle θ1 is −40 ° + (R1−43 + D3) ° <θ1 <−27 ° + (R1−43 + D3) °.

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