JP2008228495A - Ac generator for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an AC generator for a vehicle, which can prevent abnormal wear-out of a brush or generation of defects by preventing infiltration of water in a brush holder. <P>SOLUTION: The AC generator for the vehicle comprises slip rings 21, 22 provided to the rotary shaft 14 of a rotor; brushes 41, 42 that are brought into slidable contact with the outer circumferential surface of the slip rings 21, 22; a brush holder 40 and a slip ring cover 50, as a covering member for covering the circumferential space of the slip rings 21, 22 and the brushes 41, 42; a rear cover 27 covering electrical components, including the brushes 41, 42 and having a cover projection part 27A as a brush powder accommodating part for accommodating the brush powder caused by the slide movement of the slip rings 21, 22 and the brushes 41, 42; and sealing members 60, 61 for securing airtightness of the circumferential space, such as the slip rings 21, 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle AC generator mounted on a passenger car, a truck, or the like.

Conventionally, a structure in which a suction hole and a brush powder discharge hole are provided in a brush holder for the purpose of discharging brush wear powder out of the brush holder is known (for example, see Patent Document 1). By discharging the air introduced from the suction hole through the brush powder discharge hole, the brush wear powder generated by sliding with the slip ring is discharged together with this air.
JP 2000-139058 (page 3-5, FIG. 1-10)

  By the way, in the conventional structure disclosed in Patent Document 1, when the periphery of the brush holder is flooded, water enters the brush holder through the suction window and adheres to the brush, so that the brush may be worn early. However, when muddy water or salt water enters, there is a problem that the brush adheres to the brush holder and does not come into contact with the slip ring, resulting in power generation failure.

  The present invention was created in view of the above points, and its purpose is to prevent the occurrence of abnormal wear of the brush and generation of power generation by preventing water from entering the brush holder. The object is to provide a vehicle alternator.

  In order to solve the above-described problems, an AC generator for a vehicle according to the present invention includes a slip ring provided on a rotating shaft of a rotor, a brush that is in sliding contact with an outer peripheral surface of the slip ring, and a space around the slip ring and the brush. A cover member that covers the electrical parts including the brush, a protective cover that covers the electrical components including the brush and that stores brush powder generated by sliding of the slip ring and the brush, and is inserted between the cover member and the protective cover. And a sealing member for ensuring the airtightness of the surrounding space. By providing a sealing member between the covering member and the protective cover, it is possible to prevent water from entering the surrounding space of the slip ring and to prevent the brush from being discharged by increasing the airtightness of the surrounding space. By storing the powder in the brush powder storage unit, the brush powder does not adhere to the sliding surface of the slip ring and the brush, and therefore, it is possible to prevent the brush from being abnormally worn or generating power.

  It is desirable that the brush powder storage unit described above communicates with the surrounding space, and at least a part of the brush powder storage unit is disposed on the ground side of the slip ring when the vehicle is assembled. In particular, it is desirable that a part of the brush powder storage unit disposed on the ground side of the slip ring when the vehicle is assembled has a capacity capable of storing the brush powder generated when the brush is used up to the use limit. This makes it possible to reliably store the brush powder generated during power generation in the brush powder storage unit.

  It is desirable that the brush powder storage unit described above is formed to be rotatable around a rotation axis. Thereby, even if the assembly state to the vehicle is different, it can be dealt with only by adjusting the angle of the brush powder storage portion of the protective cover, so the orientation of the brush storage portion differs for each assembly state. It is not necessary to prepare a protective cover, and an increase in cost due to an increase in the number of parts can be suppressed.

  Hereinafter, an AC generator for a vehicle according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of an automotive alternator according to an embodiment. A vehicle alternator 100 shown in FIG. 1 includes a front frame 1, a rear frame 2, a stator 4, a rotor 10, a rectifier 24, a voltage controller 25, a brush device 26, a rear cover 27, and the like. Has been.

  Both the front side frame 1 and the rear side frame 2 have a bowl shape, and are fixed to each other by a plurality of bolts 3 with the stators 4 sandwiched between the openings. . A cylindrical bearing box 7 is formed integrally with the front side frame 1, and an iron bearing box 8 is attached to the rear side frame 2 with bolts 9 having knurling.

  The stator 4 includes a stator core 5 and a stator winding 6. The rotor 10 includes a field winding 11, pole cores 12 and 13, a rotation shaft 14, and the like, and is rotatably held by a pair of bearings 15 and 16 fixed to the bearing boxes 7 and 8. Centrifugal cooling fans 17 and 18 are attached to the axial end surfaces of the pole cores 12 and 13. The cooling fan 17 on the front side is a mixed flow type in which the blades are inclined forward with respect to the rotation direction of the rotor 10 in order to generate cooling air to the field winding 11. A pulley 19 is coupled to the front end of the rotating shaft 14 by a nut 20 and is driven to rotate by a vehicle engine (not shown). Further, a pair of slip rings 21 and 22 are provided at the rear end of the rotating shaft 14 located outside the rear side frame 2 and are electrically connected to the field winding 11.

  So-called electrical components such as the rectifying device 24, the voltage control device 25, and the brush device 26 are fixed to the outer axial end surface of the rear frame 2 by fixing means such as bolts 9 and the like. The rectifier 24 rectifies and converts a three-phase AC voltage, which is an output voltage of the three-phase stator winding 6, into a DC output voltage, for example. The voltage control device 25 controls the output voltage of the vehicle AC generator 100 by adjusting the excitation current flowing through the field winding 11. The brush device 26 is for passing an exciting current from the rectifier 24 to the field winding 11 of the rotor 10, and the outer peripheral surfaces of the slip rings 21 and 22 formed on the rotating shaft 14 of the rotor 10. There is a brush that slidably contacts.

  The rear cover 27 is a protective cover as an outer shell made of resin (for example, nylon) and covers electrical components such as a rectifier 24, a voltage controller 25, and a brush device 26 that are attached to the outside of the rear frame 2. To protect them. The rear cover 27 is fastened and fixed to a bolt 9 extending from the rear frame 2 by a nut 28 in a state where the rectifier 24 is sandwiched.

  In the vehicular AC generator 100 having the above-described structure, when the rotational force from the vehicle engine is transmitted to the pulley 19 via a belt or the like, the rotor 10 rotates in a predetermined direction. In this state, by applying an excitation voltage from the outside to the field winding 11 of the rotor 10, the claw portions of the pole cores 12 and 13 are excited to generate a three-phase AC voltage in the stator winding 6. A predetermined direct current is taken out from an output terminal provided in the rectifier 24.

  Next, the brush device 26 and the surrounding rear cover 27 will be described. FIG. 2 is a partially enlarged cross-sectional view around the brush device 26. The brush device 26 is configured by combining the brush holder 40 and the slip ring cover 50.

  The brush holder 40 includes brushes 41 and 42, springs 43 and 44 that press the brushes 41 and 42 against the slip rings 21 and 22, and a brush 43 in a state where one end is pressed against the springs 43 and 44. And a box-shaped holder main body 45 having a brush storage portion for storing 41 and 42. The slip ring cover 50 is for covering and protecting the slip rings 21 and 22 formed in the vicinity of the end portion of the rotating shaft 14, and has a cylindrical shape that engages with the end surface on the rotating shaft 14 side of the brush holder 40. have. In the brush device 26 of the present embodiment, a covering member that covers the space around the slip rings 21 and 22 and the brushes 41 and 42 is formed by combining the brush holder 40 and the slip ring cover 50.

  Between the brush holder 40 and the slip ring cover 50 and the rear cover 27, a flexible sealing member 60 such as rubber is disposed so as to close the gap. Similarly, a flexible seal member 61 such as rubber is disposed between the brush holder 40 and the slip ring cover 50 and the rear frame 2 so as to close the gap. By arranging these seal members 60 and 61 around the brush holder 40 and the slip ring cover 50, the airtightness of the space around the slip rings 21 and 22 and the brushes 41 and 42 is ensured.

  Further, the rear cover 27 has a cover protrusion 27 </ b> A formed so that a part of the rear cover 27 protrudes outward along the rotation axis 14 of the rotor 10. The cover protruding portion 27A is a brush storage portion that stores brush powder generated by the sliding of the slip rings 21 and 22 and the brushes 41 and 42, and communicates with the surrounding space of the slip rings 21 and 22 and the brushes 41 and 42. ing. The cover protrusion 27A has a shape in which at least a part is disposed on the ground side of the slip rings 21 and 22 when the vehicle alternator 100 is assembled to the vehicle. More specifically, the size (shape and capacity) of a partial area on the ground side is set so that the capacity of the brush powder generated when the brushes 41 and 42 are used up to the use limit is greater than the capacity that can be stored. Has been.

  Thus, in the vehicle alternator 100 of the present embodiment, the slip ring 21, the seal member 60, 61 is provided between the brush holder 40 and the slip ring cover 50 and the rear cover 27 and the rear frame 2. The airtightness of the surrounding space of 22 can be ensured to prevent the ingress of water, and the brush powder that is no longer discharged due to the increased airtightness of the surrounding space is covered protrusion 27A as a brush powder storage part. This prevents the brush powder from adhering to the sliding surfaces of the slip rings 21 and 22 and the brushes 41 and 42, thus preventing abnormal wear of the brushes 41 and 42 and generation of power generation failure due to the abnormal wear. can do.

  Further, at least a part of the cover projecting portion 27A is disposed on the ground side from the slip rings 21 and 22 when the vehicle is assembled. Specifically, a part of the cover protruding portion 27A disposed on the ground side of the slip rings 21 and 22 when the vehicle is assembled has brush powder generated when the brushes 41 and 42 are used up to the use limit. The shape is set to have a capacity that can be stored. For this reason, it becomes possible to reliably store the brush powder generated during power generation in the cover protrusion 27A.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the embodiment described above, since the cover protrusion 27A is formed by protruding a part of the rear cover 27, the position in the circumferential direction (rotation direction) around the rotation shaft 14 is fixed. A structure that can rotate in the circumferential direction may be used.

  FIG. 3 is a partial cross-sectional view of a vehicle AC generator showing a modification of the cover protrusion. FIG. 4 is a rear view of the vehicle alternator showing a modification of the cover protrusion. The rear cover 27 shown in FIGS. 3 and 4 is provided with a cover protrusion 27B that can rotate around the rotation shaft 14. The cover protrusion 27B has a shape in which the internal space is expanded in one radial direction, and the portion where the internal space is expanded is rotated so as to coincide with the ground direction when the vehicle is assembled. Can do.

  By using such a cover projecting portion 27B, even if the state of assembly to the vehicle is different, the brush projecting within the cover projecting portion 27B can be achieved simply by adjusting the angle of the cover projecting portion 27B of the rear cover 27. Since powder can be stored, it is not necessary to prepare the rear cover 27 in which the direction of the cover protrusion differs for each assembled state, and an increase in cost due to an increase in the number of parts can be suppressed.

  In the above-described embodiment, the brush device 26 is configured by combining the brush holder 40 and the slip ring cover 50. However, other configurations are possible as long as the airtightness of the space around the brushes 41 and 42 and the slip rings 21 and 22 can be secured. May be used. For example, a cylindrical member may be integrally formed on the axial end surface of the rear side frame 2 and used instead of the slip ring cover 50 (in this case, however, the cylindrical member and the brush holder 40 It is necessary to add another sealing member to ensure airtightness between them).

  In the above-described embodiment, the cover protrusion 27A protruding in one radial direction (downward in FIG. 1) is used. However, the diameter of the cover protrusion may be enlarged to have a circular shape. Thereby, it is possible to secure an internal space in which the brush powder can be sufficiently stored in the cover projecting portion regardless of the mounting state of the vehicle alternator.

It is a figure showing the whole composition of the alternator for vehicles of one embodiment. It is a partial expanded sectional view of a brush apparatus periphery. It is a fragmentary sectional view of the alternator for vehicles which shows the modification of a cover projection part. It is a rear view of the vehicle alternator which shows the modification of a cover protrusion part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front side frame 2 Rear side frame 4 Stator 10 Rotor 21, 22 Slip ring 24 Rectifier 25 Voltage control device 26 Brush device 27 Rear cover 27A Cover protrusion part 40 Brush holder 41, 42 Brush 50 Slip ring cover

Claims (4)

A slip ring provided on the rotating shaft of the rotor;
A brush in sliding contact with the outer peripheral surface of the slip ring;
A covering member covering a space around the slip ring and the brush;
A protective cover having a brush powder storage part for covering the electrical components including the brush and storing brush powder generated by sliding of the slip ring and the brush;
A sealing member that is inserted between the covering member and the protective cover to ensure the airtightness of the surrounding space;
A vehicle alternator comprising: In claim 1,
The AC generator for vehicles, wherein the brush powder storage portion communicates with the surrounding space and is at least partially disposed on the ground side with respect to the slip ring when the vehicle is assembled. In claim 2,
A part of the brush powder storage unit disposed on the ground side of the slip ring when the vehicle is assembled has a capacity capable of storing brush powder generated when the brush is used up to a use limit. AC generator for vehicles. In any one of Claims 1-3,
The AC generator for vehicles, wherein the brush powder storage portion is formed to be rotatable around the rotation shaft.

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