JP2002345198A - Ac generator for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an AC generator for a vehicle which can surely prevent foreign matters from infiltrating into a peripheral space of a brush and a slip ring and periphery of a bearing, through a mating surface of a bearing accommodating part and a frame. SOLUTION: The AC generator 1 for a vehicle is equipped with a rotor 3 for generating field magnetic flux, a rolling bearing 46 for holding the rotor 3 rotatably, and a frame 4, in which the bearing accommodating part 44 for accommodating the rolling bearing 46 is installed. The bearing accommodating part 44 is constituted of a material which is different from the frame 4, and fixed to the fixing surface of the frame 4 in the state of close contact. The frame 4 has a trench part 100 formed on the fixing surface, along the revolving direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle alternator mounted on a passenger car, a truck and the like.

[0002]

2. Description of the Related Art Conventionally, in a vehicle alternator, a brush holder or a slip ring cover has been used to prevent water or oil from entering a slip ring formed near one end of a rotating shaft of a rotor. By covering the surrounding space of the slip ring with this, the airtightness of the surrounding space is maintained. In a vehicle alternator in which a bearing accommodating portion for accommodating a rolling bearing used for rotatably supporting a rotor is mounted on a frame, the internal space of the bearing accommodating portion slips along the rotating shaft. Since it communicates with the surrounding space of the ring, it is necessary to keep the internal space airtight. For example, if the bearing housing is formed of a member separate from the frame, the outer periphery of the bearing housing is fastened and fixed to the frame with knurled bolts, so that the space between the bearing housing and the frame is secured. Close contact is made so that water, oil or other foreign matter does not enter from this mating surface.

[0003]

By the way, in the above-mentioned conventional structure, the dust-proofing effect from the outside is sufficiently ensured. However, if the periphery of the bearing accommodating part is wet or oiled, the arrow shown in FIG. As shown by, there is a risk that water or oil may enter from the mating surface of the frame and the bearing housing due to capillary action, and it is not possible to sufficiently prevent foreign substances from entering the space around the slip ring and the periphery of the bearing. was there. Such intrusion of foreign matter causes abnormal wear of the brush and the slip ring. In addition, when foreign matter such as water enters the inside of the rolling bearing, the durability of the bearing is greatly reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to allow foreign matter to enter the space around a brush or a slip ring or the periphery of a bearing through a mating surface between a bearing housing and a frame. It is an object of the present invention to provide a vehicle alternator capable of reliably preventing the occurrence of the above.

[0005]

In order to solve the above-mentioned problems, an automotive alternator according to the present invention comprises a rotor for generating a field magnetic flux, a rolling bearing for rotatably holding the rotor, and And a frame to which a bearing accommodating portion for accommodating the rolling bearing is attached. The bearing accommodating portion is formed of a separate member from the frame, and is attached in a state of being in close contact with the attachment surface of the frame. Further, the frame has a groove formed on the mounting surface along the circumferential direction. Since the groove is formed along the circumferential direction on the mounting surface of the frame, water or oil that has entered between the bearing accommodating portion and the mounting surface (matching surface) by capillary action cannot pass through the groove. . This makes it possible to reliably prevent foreign matter from entering the internal space in contact with the rolling bearing.

It is desirable that the above-mentioned groove is provided with a drainage portion at a position facing the ground when assembled to a vehicle. When water or the like that has entered due to the capillary action stays in the groove, it can be efficiently drained, so that the effect of preventing foreign matter from entering can be maintained for a long period of time.

Further, in a state where the rolling bearing is accommodated in the bearing accommodating portion, the internal space in contact with the end face of the rolling bearing in the bearing accommodating portion communicates with the space around the slip ring provided on the rotating shaft of the rotor. It is desirable to have. In the case of having such a structure, it is possible to reliably prevent foreign matter from entering the space around the slip ring together with the internal space in contact with the rolling bearing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle AC generator according to an embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of the vehicle alternator of the present embodiment. The vehicle alternator 1 shown in FIG. 1 includes a stator 2, a rotor 3, a frame 4, a brush device 5, a rectifying device 6, a rear cover 7, and the like.

The stator 2 includes a stator core 22, a three-phase stator winding 23, and an insulator 24 for electrically insulating the stator core 22 and the stator winding 23 from each other.
The rotor 3 has a structure in which a field winding 31 in which an insulated copper wire is wound cylindrically and concentrically is sandwiched from both sides through a rotating shaft 33 by pole cores 32 each having six claws. have. Further, a cooling fan 35 for discharging the cooling air sucked from the front side in the axial direction and the radial direction is attached to an end face of the pole core 32 on the front side by welding or the like. Similarly,
A cooling fan 36 for discharging the cooling air sucked from the rear side in a radial direction is attached to an end face of the rear pole core 32 by welding or the like. Also, the rotating shaft 33
In the vicinity of the rear end of the motor, two slip rings 37 and 38 electrically connected to both ends of the field winding 31 are formed. Power is supplied to the field winding 31.

The frame 4 accommodates the stator 2 and the rotor 3. The rotor 3 is supported rotatably about a rotation shaft 33, and the outer periphery of the pole core 32 of the rotor 3. Is fixed to the stator 2 disposed with a predetermined gap therebetween. The rotor 3 is supported by a pair of rolling bearings 46 and 47 housed in bearing housings 44 and 45 provided on the frame 4. The rear bearing accommodating portion 44 is fastened and fixed substantially in the center of the inner surface of the rear frame 4 in a state of being brought into close contact with the mating surface, and accommodates one rolling bearing 46 with a predetermined interference. Further, the front-side bearing accommodating portion 45 is a concave portion provided substantially at the center of the inner surface of the front-side frame 4, and accommodates the other rolling bearing 47 with a predetermined interference.

The frame 4 has a discharge window 41 for cooling air at a portion facing the stator winding 23 protruding from the axial end face of the stator core 22, and has a suction window 42 at the axial end face. ing. The brush device 5 includes the rectifier 6 and the rotor 3.
And a slip ring 37 formed on the rotating shaft 33 of the rotor 3.
38 are provided with brushes 51 and 52 for pressing the respective brushes.

The rectifier 6 rectifies a three-phase AC voltage, which is an output voltage of the three-phase stator winding 23, to obtain DC output power. The rear cover 7 covers and protects electrical components such as the brush device 5, the rectifier 6, and the IC regulator 9, which are attached to the outside of the rear frame 4, and protects them. The rear cover 7 is fastened and fixed to a bolt 43 extending from the rear frame 4 by a metal nut 71 with the rectifying device 6 sandwiched therebetween. The rear cover 7 is mainly composed of the rectifying device 6.
Has a plurality of suction windows on its opposite surface, and cooling air is sucked into the rear cover 7 through the suction windows.

An alternator 1 for a vehicle having the above-described structure.
Is connected to the pulley 8 via a belt or the like by an engine (not shown).
When the rotational force is transmitted, the rotor 3 rotates in a predetermined direction. In this state, by applying an excitation voltage to the field winding 31 of the rotor 3 from the outside, the respective claws of the pole core 32 are excited, and a three-phase AC voltage can be generated in the stator winding 23. A predetermined DC current is taken out from an output terminal provided in the rectifier 6.

Next, the structure around the rear bearing housing 44 will be described. FIG. 2 shows the rear bearing housing 4
4 is a partial cross-sectional view showing a structure around 4. As shown in FIG. 2, the brush device 5 includes a brush holder 53 that stores two brushes 51 and 52, and a slip ring cover 54 that covers the outer circumference of the slip rings 37 and 38 together with the brush holder 53. ing. A cylindrical body constituted by a brush holder 53 and a slip ring cover 54, and a space 5 around two slip rings 37 and 38.
The airtightness of the surrounding space 55 is maintained by covering the space 5. The surrounding space 55 communicates with the internal space 48 that is in contact with the rear end surface of the rolling bearing 46 in the rear bearing housing portion 44.

FIG. 3 is a plan view showing the detailed shape of the rear bearing housing portion 44. As shown in FIG. As shown in FIG. 3, the bearing housing portion 44 includes a central annular portion 108 and the annular portion 108.
A flat portion 110 formed at a predetermined width outward from the one end in the circumferential direction, and three extension portions 114 extending further outward from the flat portion 110 in the circumferential direction. Each extension 1
A bolt hole 112 is formed in 14. The bolt 43 partially formed with a knurl portion is inserted into the bolt hole 112, and the mounting of the bearing housing portion 44 to the rear frame 4 is performed. At this time, the mounting of the bearing housing portion 44 is performed in a state where the end surface of the flat portion 110 is in close contact with the mating surface (mounting surface) of the frame 4.

A groove 100 is formed in the mounting surface of the frame 4 along the circumferential direction. This groove 1
The opening 00 is closed by the flat portion 110 of the bearing housing portion 44 when the bearing housing portion 44 is attached to the frame 4. Further, a drain portion 102 extending radially outward is formed in a part of the groove 100. As shown in FIG. 2, a part of the drainage part 102 is exposed to the internal space of the frame 4 with the bearing housing part 44 attached to the frame 4. In addition, this drain section 10
Reference numeral 2 is formed at a position facing the ground direction on the opposite side to the ceiling direction with the vehicle alternator 1 assembled to the vehicle.

FIG. 4 is a view showing a state in which water or the like has entered a groove and a drain formed in the frame. As shown by arrows in FIG. 4, water or the like that has entered from outside in the radial direction due to capillary action flows into the groove 100 and stays there,
Thereafter, the water is drained from the drain section 102.

As described above, in the automotive alternator 1 of the present embodiment, the groove 100 is formed along the circumferential direction on the mounting surface of the frame 4 facing the bearing housing portion 44 on the rear side. For this reason, water or oil that has entered between the bearing housing portion 44 and the mounting surface due to the capillary action is removed from the groove 1.
00 and cannot stay in the groove 100.
Accordingly, it is possible to reliably prevent foreign matter from entering the internal space 48 in contact with the rear-side rolling bearing 46.

Further, by providing the drainage portion 102 in a part of the groove portion 100, if water or the like that has entered due to the capillary phenomenon stays in the groove portion 100, it can be efficiently discharged, and foreign matter can be removed. The effect of preventing intrusion can be maintained for a long time.

Further, by preventing foreign matter from entering the internal space 48 in contact with the rear-side rolling bearing 46, foreign matter can be prevented from entering the surrounding space 55 of the slip rings 37 and 38 communicating with the internal space 48. It can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a vehicle alternator according to an embodiment.

FIG. 2 is a partial cross-sectional view showing a structure around a bearing housing portion on the rear side.

FIG. 3 is a plan view showing a detailed shape of a rear bearing housing portion.

FIG. 4 is a diagram showing a state in which water or the like has entered a groove and a drain formed in a frame.

FIG. 5 is a view showing a state in which water or the like has entered in a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Stator 3 Rotor 4 Frame 5 Brush device 37, 38 Slip ring 44, 45 Bearing accommodating part 46, 47 Rolling bearing 53 Brush holder 54 Slip ring cover 100 Groove part 102 Drainage part

Claims (3)

[Claims] 1. An alternator for a vehicle, comprising: a rotor that generates a field magnetic flux; a rolling bearing that rotatably holds the rotor; and a frame on which a bearing housing that houses the rolling bearing is mounted. In the above, the bearing accommodating portion is formed of a separate member from the frame, and is attached in a state of being in close contact with an attachment surface of the frame. The frame is formed on the attachment surface along a circumferential direction. An alternator for a vehicle, comprising: a groove. 2. The vehicle alternator according to claim 1, wherein a drain portion is provided in the groove portion at a position facing the ground when the groove portion is assembled to the vehicle. 3. The internal space in contact with the end surface of the rolling bearing in the bearing housing portion in a state where the rolling bearing is housed in the bearing housing portion, according to claim 1 or 2, An alternator for a vehicle, wherein the alternator communicates with a space around a slip ring provided.