MXPA99001070A - Alternating current generator for mo ve vehicles - Google Patents

Abstract

An alternating current generator for a motor vehicle is provided, wherein a front cantilever is constructed in a bowl-like configuration comprising primarily a section accommodating a bearing placed in its central portion, four sections of insertion of through bolts placed at an equiangular pitch on the same circumference and four reinforcement or rib sections, each to constitute a connection between the section accommodating a bearing and each of the through bolt insertion sections, and inlet openings are provided in each of the areas between the reinforcing sections while leaving openings so each of the areas between the insertion sections of through bolts. In addition, the total number of inlet openings is 14, different from the total number (12) of hook-like magnetic pole portions, and outlet openings are further provided on the insertion section sides of through bolts of the reinforcing sections.

Description

GENERATOR OF CO-RRIEMTB ALTER-H ------ FOR VEHi iOS OF M-OR BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to an alternating current generator for a motor vehicle, equipped with a Lundell type rotor, which is to be mounted on a motor vehicle engine, and more particularly with a front bracket construction of a power generator. alternating current for a motor vehicle which reduces a high-grade or high-order component of the fluid produced by the wind that results from the rotation of the rotor.

DESCRIPTION OF THE TF.c * pr TCT, A tpr-r > ? Figure 3 is a front elevational view of an anterior motor vehicle AC generator viewed from its front side, and Figure 4 is a cross-sectional view taken along the line IV-IV. In Figure 3 a pulley is omitted for illustration. The above motor vehicle AC generator is constructed in such a way that Lundell-type rotor 7 is rotatably placed through a shaft 6 inside a cover comprising a front bracket 1 and a rear bracket 2, made of aluminum, while a stator 8 is fixedly secured to the cover to cover the outer circumferential side of the rotor 7. The front bracket 1 has a bowl-like construction comprising primarily a section 30 accommodating a bearing positioned in a central portion, four sections 31 of insertion of bolts located at an equiangular pitch on the same circumference, and four reinforcing or rib sections 32 to make a connection between the section 30 accommodating a bearing and each of the through bolt insertion sections 31. In addition, three inlet openings are provided at each of the locations between the reinforcing sections 32 in the circumferential direction, while a plurality of outlet openings Ib are fabricated at each of the locations between the insertion sections 31. through bolt in the circumferential direction. In addition, the rear bracket 2 has a bowl-like configuration that includes a section 33 accommodating a bearing positioned in a central portion and four sections 34 that accept through bolts located in an equiangular passage over an identical circumference, with a plurality of openings 2a of inlet fabricated on an outer circumference of the section 33 accommodating a bearing while providing a plurality of outlet openings 2b at each of the locations between the sections 34 that accept the through bolts in the circumferential direction. Furthermore, the through bolts 35 inserted into the cross-bolt insertion sections 31 of the front bracket 1 are respectively placed in the sections 34 that accept the through bolts of the rear bracket 2 for a clamping connection between them and this way an integral relationship is produced. The shaft 6 is rotatably supported by bearings 3, 4, housed respectively in the sections 30, 33 accommodating a bearing in the front and rear brackets 1, 2. A pulley 5 is fixedly placed on an end portion of the shaft 6 to transfer a rotational torque movement of a motor through a belt (not shown) to the shaft 6. A sliding ring 9 for supplying a current to the rotor 7 is fixedly placed on the other end portion of the shaft 6, and a carbon or brush 10 is placed on a carbon support 11 placed on the cover to make sliding contact with the 9 sliding ring. In addition, a voltage regulator 18, which regulates the output voltage of the stator 8, adheres to a heat sink 17 placed on the carbon support 11. Additionally, a rectifier 12 electrically connected to the stator 8 and rectifying the alternating current generated in the --- stator 8 in direct current is placed on the cover. The rotor 7 is composed of a rotor coil 19 for generating a magnetic flux in response to an electric current and a pair of field cores 20, 21 provided to cover this rotor coil 19 and to be the magnetic poles as a result of the flux. magnetic produced by the rotor coil 19. 1 pair of field cores 20, 21 are made of iron, each having 6 magnetic pole portions 20a or 21a similar to trapezoidal hooks placed in a protruding manner in an equiangular pitch in the circumferential direction and both fixedly placed on the shaft 6 in an opposite relation to each other so that their magnetic portions 20a, 21a similar to hooks are capable of coupling with each other. In addition, fans 13, 14, respectively, having vanes 13a, 14a are fixedly attached to both end portions of the rotor 7 in their axial directions. The stator 8 is constituted by a stator core 15 and a stator coil 16 manufactured by winding a conductor or wire to the stator core 15 and in which an alternating current is generated by alternating the magnetic flux of the rotor 7 with the rotation of the rotor 7. In previous motor vehicle AC generators constructed in this way, current is supplied from a battery (not shown) through the carbon 10 and the sliding ring 9 to the rotor coil 19, so that a magnetic flux is regulated. Due to its magnetic flux, the magnetic pole portions 20a similar to hooks of a core Fields are magnetized to polarities N while the hook-like magnetic pole portions 21a of the other field core 21 are magnetized to S polarities. On the other hand, the rotational torque of the motor is transferred through the band and the pulley 5 to the shaft 6, which causes "the rotor 7 to rotate.Therefore, a rotational magnetic field is provided to the stator coil 16 so that the electromotive force takes place in the stator coil 16. This force Electromotive alternating current passes through the rectifier 12 to be rectified in direct current, its voltage is regulated by the voltage regulator 18 and the battery is charged.Further, on the front side, the fan 13 rotates so that the air cooling is sucked from the inlet openings of the front bracket 1 as indicated by the arrow A to cool the bearing 3, the field core 20, the rotor coil 19, the stator core 15 and the coil to 16 stator, and then discharged through the exit openings Ib to the outside. Meanwhile, on the rear side, due to the rotation of the fan 14, the cooling air is sucked from the inlet openings 2a of the rear bracket 2, as indicated by an arrow B to cool the bearing 4, the regulator 18 of voltage, the rectifier 12, the field core 21, the rotor coil 19, the stator core 15 and the stator coil --- 16, and then discharged at Eravés from the outlet openings 2b towards the outside. - = - Since the AC generator of the above motor vehicle is constructed as described above, by the rotations of the field cores 20, 21, a pressure fluctuation occurs resulting from the presence or absence of the hook-like magnetic pole portions 20a, 21a in the outer circumferential sections of the field cores 20, 21 which causes a sound pressure of the noise produced by the wind to become noticeably greater with the twelfth degree frequency which corresponds to the total number (12) of hook-like magnetic pole portions 20a, 21a, so that it can be annoying to the ear and increases the overall sound pressure level.

BRIEF DESCRIPTION OF THE INVENTION This applicant has considered this problem and has intensively examined it, and as a result, has found that a sound pressure of the noise produced by the wind with a frequency of one degree corresponding to the total of magnetic pole portions similar to hook it is remarkably increased if the total of hook-like magnetic pole portions coincides with the total number of inlet openings, with a balance of ventilation resistance to the circumferential direction on the inlet side affecting "the noise produced by the wind, and the totality of the ventilation resistance that affects the noise produced by the wind which depends considerably on the output resistance on the output side. This has led to the present-invention. That is, an object of this invention is to provide an alternating current generator for a motor vehicle which is capable of optimizing the balance of ventilation resistance on the inlet side by making a difference between the total number of inlet openings and the total number of magnet pole portions similar to hooks, and decrease the sound pressure of the noise produced by the wind with a frequency of one degree that matches the total number of hook-like magnetic pole portions by reducing the output resistance on the output side, so that the total sound pressure level decreases and the annoying sensation for the ordo can be eliminated. In order to obtain the above objective, according to one aspect of the invention, there is provided an alternating current generator for a motor vehicle comprising a rotor in which a pair of core fields, each with a plurality of trapezoidal hook-like magnetic pole portions projecting from their outer circumferential edge section are fixedly placed on a shaft that is in an opposite relationship - between them for coupling to each other, a front bracket which has a bowl-like configuration which mainly comprises a section accommodating a bearing placed in its central portion, four insertion sections of through bolts placed in an equiangular passage over the same circumference and four reinforcing sections, each to constitute a connection between the section accommodating the bearing Inete and each of the through bolt insertion sections and in which a plurality of inlet openings in each of the places between the reinforcing sections in their circumferential direction and a plurality of outlet openings that are provided at each of the locations between the through bolt insertion sections in their circumferential direction and which support a front side of the shaft through a bearing accommodated within the section accommodating the bearing, the rear bracket which has a bowl-like configuration and includes a section accommodating a bearing placed in its central portion and four sections that accept bolts lugs made in an equiangular passage over the same circumference and in which a plurality of inlet openings are provided on a cyclunferential side of the bearing accommodating section and a plurality of outlet openings are provided at each of the locations between the openings. sections that accept through bolts in their circumferential direction and which support a rear side of the shaft through a bearing housed in the - section accommodating a bearing, a stator fixedly secured to both brackets to encircle an outer circumference of the pair of field cores in a manner that the through bolts are placed within of the through bolt insertion sections in the sections that accept through bolts of both brackets are tightened, and a pair of fans fixedly secured, respectively, to the end surfaces of the pair of field cores 5 in their axial directions to produce cooling air introduced through the inlet openings inside the front and rear brackets, where the total number of inlet openings manufactured in the front bracket differs from the total number of the magnetic pole portions JO similar to hooks of the pair of field cores and the exit openings are placed on the sides of insertion section of through-bolt sections of reinforcement of the front bracket.

BRIEF DESCRIPTION OF THE DRAWINGS 15 Figure 1 is a front elevation view showing an alternating current g-enerator for a motor vehicle, according to a first embodiment of the present invention, observed from its front side; 20 'Figure 2 is a cross-sectional view taken along a line II-II of Figure 1; Figure 3 is a front elevational view showing an anterior motor vehicle AC generator, viewed from its front side; and Figure 4 is a cross-sectional view taken along a line IV-IV of Figure 3.

DESCRIPCTÓM npTAT.T.?D? ? V T.? PREFERRED MODALITY Next, an embodiment of the present invention will be described with reference to the drawings.

First Modality Fig. 1 is a front elevation view showing an alternating current generator for a motor vehicle according to a first embodiment of the present invention, seen from its front side, and Fig. 2 is a cross-sectional view taken at along line II-II of figure 1. In figure 1 a pulley is omitted for illustration. In Figures 1 and 2, a front bracket 50 made of aluminum is formed within a bowl-like configuration comprising primarily a section 51 accommodating a bearing placed in its central portion, four through bolt insertion sections 52 placed in a equiangular pitch on the same circumference and four reinforcing sections 53, each to form a connection between the section accommodating a bearing and each of the through bolt insertion sections 52, and a set of three openings 50a inlet and a set of four inlet openings 50a are alternately fabricated in places or areas between the reinforcement sections 53 in the circumferential direction while manufacturing a plurality of outlet openings 50b at each of the locations between the insertion sections 52 of through bolt in the circumferential direction, and additionally, an outlet opening 50c is provided on a section 52 of -i lateral stud bolt to each of the reinforcement sections 53. In addition, the through bolts 35 are inserted into the through bolt insertion sections 52 of the front bracket 50, and tightened within the sections 34 that accept the through bolt of the rear bracket 2 so that both circumferential end portions exteriors of a stator core 15 are held by the opening edge portions of the front bracket 50 and the rear bracket 2 for fixing a stator 8. Incidentally, this motor vehicle AC generator is constructed as the current generator alternating motor vehicle shown in Figures 3 and 4, except for the use of the front bracket 50 that replaces the front bracket 1. On the front side of the motor vehicle AC generator according to the first embodiment, due to the rotation of a fan 13, the cooling air is sucked from the inlet openings 50a of the front bracket 50, as indicated by an arrow A to cool a bearing 3, a field core 20, a rotor coil 19, a stator core 15 and a stator coil 16, and then discharge through the outlet openings 50b, 50c to the Exterior. On the other hand, on the rear side, the rotation of the fan 14 causes the cooling air to be introduced from the inlet openings 2a of the rear bracket 2 as indicated by an arrow B to cool a bearing 4, a voltage regulator 18, a rectifier 12, a field core 21, the rotor coil 19, the de-stator core 15 and the stator coil 16, and then discharged after the outlet openings 2b to the outside. According to the first embodiment, since the 14 input openings 50a differ in number from the total (12) of the hook-like magnetic pole portions 20a and 21a, are manufactured in the front bracket 50, it is possible to decrease the sound pressure of the noise produced by the wind with a frequency of twelfth degree corresponding to the total number of portions 20a, 21a of magnetic poles similar to hooks. Still further, in addition to the plurality of outlet openings 50b manufactured at each of the locations between the through-bolt insertion sections 52 in the circumferential direction, the outlet opening 50c is provided on the side of the insert -52 section. of through bolt of each of the reinforcement sections 53, and therefore the total area of the outlet openings is increased to reduce the output side ventilation resistance, thereby decreasing the total ventilation resistance that has influence about the noises produced by the wind. As a result, it is possible to provide a motor vehicle AC generator which is capable of lowering the total sound pressure level value and eliminating the annoying sensation to the ear. Further, since a set of three inlet openings 50a and a set of four inlet openings 50a are alternately provided in four areas defined by the reinforcement sections 53 in the circumferential direction, the ventilation resistance on the inlet side of the front bracket 50 is well balanced in the circumferential direction, so that the noise produced by the wind is reduced. That is, the arrangement of the inlet openings in the first embodiment offers a better balance of the ventilation resistance of the inlet side in the circumferential direction, as compared to the case in which the inlet opening assemblies, all different in number of inlet openings therebetween, are provided in the four areas defined by the reinforcement sections 53 or the case in which three inlet openings are made in a set of adjacent areas while four inlet openings are manufactured in another set of adjacent areas.

Additionally, since the 14 inlet openings 50a are provided with respect to the 12 portions 20a, 21a Magnetic pole W similar to hook, it is possible to maximize the total area of the opening 50a inlet and at the same time maintain a good balance of the ventilation resistance of the inlet side of the front bracket 50 in the circumferential direction.

If the inlet openings 50a are 13, although the total area of the inlet openings 50a is increased, the circumferential balance of the ventilation resistance- '10 is deteriorated. Furthermore, if the inlet openings 50a are 15 or more, the area total of the input SOa areas results in a reduction. In the first embodiment described in the foregoing, although 14 inlet openings 50a are provided with respect to 12 hook-like magnetic pole portions 20a, 21a, the total 15 of inlet openings 50a is not limited to 14, but is acceptable in the extent to which the total number of hook-like magnetic pole portions 20a, 21a differs from the total number of inlet openings 50a. In addition, although the above description indicates that the The first embodiment described above is applied to an AC generator of a motor vehicle in which the total number of magnetic poles similar to hooks 20a, 21a is 12, this invention is not limited to this, but is also applicable to others. motor vehicle AC generators in which the total number of hook-like magnetic pole portions is different from that mentioned. In this case, similar effects are obtainable. The construction described in the above, in accordance with this invention, shows the following effects. According to this invention, there is provided an alternating current generator for a motor vehicle comprising a rotor in which a pair of field cores are fixedly placed, each having a plurality of hook-like, trapezoidal magnetic pole portions. , protruding from its outer circumferential edge section, on a shaft that is in an opposite relation to each other for coupling, a front bracket which has a bowl-like configuration comprising mainly a section accommodating a bearing placed in its central portion, four through bolt insertion sections placed at an equiangular pitch on the same circumference and four reinforcement sections, each to make a connection between the section accommodating a bearing and each of the through bolt insert sections, and in which a plurality of input openings are provided in each of the places between the reinforcing sections in their circumferential direction and a plurality of outlet openings that are provided at each of the locations between the through bolt insertion sections in their circumferential direction and which supports a front side of the shaft through a bearing accommodated Within the section that accommodates a bearing, a rear bracket which has a bowl-like configuration that includes a section accommodating a bearing placed in its central portion and four sections that accept through bolts manufactured at a triangular pitch on the same circumference and in which a plurality of inlet openings are provided on an outer circumferential side of the section accommodating a bearing, and a plurality of outlet openings are provided at each of the locations between the sections that accept the through bolts in their circumferential direction and which support the back side of the tree through a co rider housed in the section accommodating the bearing, a stator fixedly secured to both brackets to encircle an outer circumference of the pair of field cores in a manner that the through bolts are placed within the through bolt insertion sections and the sections that They accept the through bolts of both brackets and tighten, and a pair of fans fixedly secured, respectively, to the end surfaces of the pair of field cores in their axial directions to produce cooling air introduced through the inlet openings in the front and rear brackets, wherein the number Total of the inlet openings made in the front bracket differs from the total number of pole-like magnetic poles of the field core pair and the outlet openings are placed on the through-bolt insert section sides of the sections of reinforcement of the front bracket, and therefore, the sound pressure of a noise produced by the wind is decreased with a frequency of one degree that coincides with the total number of the magnetic pole portions similar to hook, so that the Motor vehicle AC current generator is affordable and which is capable of decreasing the total sound pressure level value and of Limit the annoying sensation to the ear. In addition, the total number of hook-like magnetic pole portions of the pair of field cores is 12, while the total number of inlet openings produced in the front bracket is 14, and that of the inlet openings, a set of three inlet openings and a set of four inlet openings are alternately provided in four areas defined by the reinforcement sections in the circumferential direction, and therefore the inlet side ventilation resistance is well balanced in the circumferential direction, thus that the noises produced by the wind are reduced.

Claims (2)

1. An AC generator for a motor vehicle, characterized in that it comprises: a rotor in which a pair of cores are fixedly positioned, each with a plurality of magnetic pole portions similar to trapezoidal hooks protruding from their circumferential edge section outside, on a tree that is in an opposite relation to each other for coupling between Si; a front bracket which has a bowl-like configuration comprising mainly a section accommodating a bearing placed in its central portion, four insertion sections of through bolts placed in an equiangular pitch on the same circumference and four sections of reinforcement or rib, each to form a connection between the section accommodating a bearing and each of the through bolt insertion sections and in which a plurality of entry openings are provided at each of the places between the reinforcement sections in their direction circumferential and a plurality of outlet openings are provided at each of the locations between the through bolt insertion sections in their circumferential direction and which supports a front side of the shaft through a cushion accommodated within the accommodating section. a bearing; a rear bracket which has a bowl-like configuration and which includes a section accommodating a bearing placed in its central portion and four sections that accept through bolts manufactured at an equiangular pitch on the same circumference and in which a plurality of inlet openings on an outer circumferential side of the section ique accommodates a bearing, and a plurality of outlet openings are provided at each of the locations between the sections that accept through bolts in their circumferential direction and which support a rear side of the housing. tree through a bearing housed in the section that accommodates a bearing; a stator fixedly secured to the front and rear brackets to encircle an outer circumference of the pair of field cores in a manner that the through bolts are placed within the insertion sections of through bolts and the sections that accept the through bolts of the brackets front and rear are tightened; and a pair of fans fixedly secured, respectively, to the end surfaces of the pair of field cores in their axial directions to produce cooling air introduced through the inlet openings within the front and rear brackets, wherein the number total of inlet openings produced in the front bracket differs from the total number of magnetic poles similar to the hook of the pair of field cores, and the outlet openings are placed on the sides of the through bolt insert section of the sections of reinforcement of the front bracket.

2. The alternating current generator for a motor vehicle, according to claim 1, characterized in that the total number of hook-like magnetic pole portions of the pair of field cores is 12, while the total number JO of inlet openings produced in the front bracket is 14, and of the inlet openings, a set of three inlet openings and a set of four inlet openings are alternately provided in four defined areas by the reinforcing sections in a circumferential direction.