JP4223910B2 - Rotating electrical machine manufacturing method and rotating electrical machine - Google Patents

Description

  The present invention relates to a rotating electrical machine manufacturing method and a rotating electrical machine, and more particularly, to a rotating electrical machine manufacturing method and a rotating electrical machine including a brush that supplies power to a commutator.

  A rotating electrical machine is applied as a drive source for an electric power steering device of an automobile or the like. Some rotary electric machines (DC motors, etc.) have brushes. In a rotating electric machine equipped with such a brush, the brush is assembled in a state where it is pressed against the peripheral surface of the commutator, and the commutator is rotated after assembly to slightly wear the sliding surface of the brush. The sliding state between the brush and the commutator is adjusted to stabilize (so-called running process).

  However, since it takes a long time to perform the running process, it causes a decrease in productivity of the rotating electrical machine and an increase in production cost. In particular, for the rotating electrical machine applied to the electric power steering device described above, the processing time is required to be longer in order to suppress the rotational noise after the adjustment, and the reduction in productivity and the increase in production cost are remarkable. It was.

  As an invention for shortening the time for performing such a running treatment, there is an invention in which the peripheral surface of the commutator is previously slid with a brush for familiarization and the peripheral surface of the commutator is covered with a carbon film, which is disclosed in Patent Document 1 below. Has been.

However, the invention described in Patent Document 1 removes burrs and the like on the peripheral surface of the commutator by sliding the peripheral surface of the commutator with a familiar brush, or covers the peripheral surface of the commutator with a carbon film. In order to suppress the occurrence of sparks on the peripheral surface, it is affected if the assembly accuracy of the brush after assembly (installation brush replaced with a familiar brush) is poor. End up. For this reason, at the time of a drive, there existed a fault that the sliding state of a brush and a commutator was not stabilized and rotation noise could not be suppressed enough.
JP 2003-134746 A

  In view of the above problems, the present invention shortens the running time after assembling the assembly or eliminates the running process itself, and can improve the productivity of a rotating electrical machine with low noise and high rotational reliability, and can reduce the production cost. An object of the present invention is to provide a method of manufacturing a rotating electrical machine and a rotating electrical machine.

A method of manufacturing a rotating electrical machine according to a first aspect of the present invention includes: a commutator; a plurality of brushes arranged in a state of being pressed against the commutator and facing a circumferential surface of the commutator along a circumferential direction of the commutator; the end frame in which the plurality of brushes are assembled, in the manufacturing method of a rotating electric machine and a subassembly step of assembling a plurality of brushes to the end frame, the outer diameter substantially the is a cylindrical said commutator A first step in which a polishing member having the same outer diameter is disposed in advance in an original assembly position of the commutator between the plurality of brushes, and a peripheral surface of the polishing member is brought into contact with the brush; and the polishing member A second step of rotating the brush to wear a predetermined amount, removing the polishing member, arranging the commutator in the original assembly position instead of the polishing member, and surrounding the commutator The bra Characterized by comprising a third step of contacting the.

  According to the method for manufacturing a rotating electrical machine according to the first aspect of the present invention, in the first step, a plurality of polishing members that are cylindrical and have an outer diameter that is substantially the same as the outer diameter of the commutator are provided in advance. It arrange | positions in the original assembly position of the commutator between brushes, and the surrounding surface of an abrasive member is made to contact a brush.

  Next, the process moves to the second step. In this second step, the polishing member is rotated and the brush is worn by a predetermined amount.

  When the second step is completed, the process proceeds to the third step. In this third step, the polishing member is removed, and the commutator is disposed at the original assembly position in place of the polishing member. In this case, the circumferential surface of the commutator is brought into contact with the brush.

  In this way, the brush is worn by the polishing member having an outer diameter that is substantially the same as the outer diameter of the commutator, so the brush is worn to the same extent as when the running process is performed. Therefore, a rotating electrical machine with low noise and high rotational reliability can be manufactured.

  When the rotating electrical machine is manufactured in this manner, the sliding surface of the brush is already worn to some extent at the time of assembly, so that the running processing time after assembly is shortened, or the running processing itself becomes unnecessary. Therefore, the productivity of the rotating electrical machine can be improved.

  Moreover, since the running process time is shortened or the running process is not necessary, the production cost of the rotating electrical machine can be reduced.

  According to a second aspect of the present invention, there is provided a method for manufacturing a rotating electrical machine according to the first aspect of the invention, wherein the polishing member is a grindstone.

  According to the method for manufacturing a rotating electrical machine according to the second aspect of the present invention, the brush is worn by the grindstone. Here, by selecting the roughness of the grindstone as appropriate according to the hardness of the brush, optimum polishing with low sliding resistance (resistance generated between the brush and commutator) when the rotating electrical machine is driven after assembly is assembled. A surface (sliding surface of the brush) can be obtained.

  According to a third aspect of the present invention, there is provided a method of manufacturing a rotating electrical machine according to the first aspect of the invention, wherein the abrasive member is a cylindrical roll, and a sand paper wound around a peripheral surface of the roll. It is characterized by having.

  According to the method for manufacturing a rotating electrical machine according to the invention of claim 3, since the sandpaper is wound around the peripheral surface of the cylindrical roll, the peripheral surface of the roll is replaced with a configuration in which the polishing member is a grindstone. Alternatively, the brush may be worn by sandpaper wound around the paper. Here, in the configuration in which the brush is worn by the sandpaper wound around the peripheral surface of the roll, the roughness of the sandpaper is appropriately selected according to the hardness of the brush, so that the sliding resistance when the rotating electrical machine is driven after assembly is assembled. An optimum polished surface (sliding surface of the brush) having a small (resistance generated between the brush and the commutator) can be obtained.

  A rotating electrical machine according to a fourth aspect of the invention is manufactured by the method for manufacturing a rotating electric machine according to any one of the first to third aspects.

  According to the rotating electric machine according to the fourth aspect of the present invention, since the brush is worn by the polishing member having the same outer diameter as the outer diameter of the commutator, the brush is the same as when the running process is performed. Worn to a degree. Accordingly, it is possible to drive with low noise and to improve rotational reliability.

  In addition, since the sliding surface of the brush has already been worn to some extent at the time of assembly, the running process time after assembly is shortened or the running process itself becomes unnecessary. Therefore, when manufacturing a rotating electrical machine, the manufacturing time per rotating electrical machine is shortened, so that the productivity of the rotating electrical machine can be improved.

  Moreover, since the running process time is shortened or the running process is not required in this way, the production cost per rotating electric machine can be reduced when the rotating electric machine is manufactured.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing the overall configuration of a motor 10 as a rotating electrical machine according to the present embodiment.

  A yoke 12 is fixed to the housing 18 of the motor 10. The yoke 12 is formed in a cylindrical shape in which one axial end portion of the motor 10 is drawn, and a bearing 16 is disposed on the bottom portion 14 of the yoke 12. On the other hand, a bearing 20 is provided at the other axial end of the motor 10.

  The bearing 20 is disposed in the central portion of the housing 18 in a direction orthogonal to the axial direction of the motor 10. The shaft 24 of the armature 22 is supported by the bearing 20 and the bearing 16 of the yoke 12, and the armature 22 is accommodated in the yoke 12. A magnet 26 is fixed to the inner peripheral wall of the yoke 12 facing the armature 22.

  An end frame 28 is disposed between the armature 22 and the bearing 20. The end frame 28 is formed of a thin synthetic resin, and is positioned on the side of the bearing 20 and fixed to the housing 18.

  A plurality of (four in this embodiment) brush holders 34 are integrally provided on the end frame 28 along the peripheral surface 23A of the commutator 23 of the armature 22 (see FIG. 3). These brush holders 34 are made of metal and have a longitudinal direction in the direction orthogonal to the axial direction of the armature 22 (more specifically, the commutator 23 of the armature 22). Part) is formed in an open box shape (see FIG. 2).

  Inside each brush holder 34 is the longitudinal direction of the brush holder 34 (that is, the direction close to and away from the peripheral surface 23A of the commutator 23 of the armature 22 and the radial direction of the commutator 23). A carbon brush 38 is housed together with the spring 40 so as to be slidable along the spring. The brush 38 is formed in a prismatic shape, and a slight clearance is set between the side surface and the brush holder 34. Further, the front end surface of the brush 38 is a sliding surface 39 that slides on the peripheral surface 23A of the commutator 23, and is formed in a circular arc shape so as to be in close contact with the peripheral surface 23A of the commutator 23.

  On the other hand, the spring 40 always urges the brush 38 in a direction in which the brush 38 protrudes from the brush holder 34. Thereby, the brush 38 is press-contacted with the commutator 23 of the armature 22 (more specifically, the peripheral surface 23A of the commutator 23). Further, a coupling pigtail 42 is drawn out from the brush 38, and the tip of the pigtail 42 is connected to a connection line for power feeding.

  When the sliding surface 39 of the brush 38 described above is worn by a predetermined amount, as shown in FIG. 2, the motor 10 is assembled in a columnar shape with the outer diameter of the commutator 12. A grindstone 44 as a polishing member having substantially the same outer diameter is disposed at the original assembly position of the commutator 23, and the grindstone 44 is rotated around its axis to wear the sliding surface 39 of the brush 38. (FIG. 2 shows a state in which a part of the sliding surface 39 of the brush 38 is in contact with the grindstone 44).

  The operation of the embodiment of the present invention will be described below.

  Immediately after the assembly of the motor 10, due to variations due to the accuracy of single parts of the components assembled in the motor 10, variations in the assembly accuracy of these components, and rattling between the brush 38 and the brush holder 34, etc. 3, all of the sliding surfaces 39 of the brushes 38 are not located on the circumference of a perfect circle around the axis of the commutator 23. Contact with the sliding surface 39 of each brush 38 becomes unstable, causing problems such as deterioration of noise and noise, and unstable characteristics.

  Therefore, as shown in FIG. 2, the following processing is performed before assembly of the motor 10 and in the sub-assembly state in which the brush 38 and the spring 40 are assembled to the end frame 28.

  First, an external force against the urging force of the spring 40 is applied to the sliding surface 39 of each brush 38, and each brush 38 is moved to the side opposite to the urging direction of the spring 40. That is, the space of the original assembly position of the commutator 23 provided between the four brushes 38 (more specifically, between the sliding surfaces 39 of the four brushes 38) is expanded. Next, when the grindstone 44 having a cylindrical shape and having an outer diameter substantially the same as the outer diameter of the commutator 12 is disposed in the expanded space, the application of the external force is released in this state. The peripheral surface of the grindstone 44 is brought into contact with the brush 38. In this state, rattling remains between the grindstone 44 and each brush 38 (the first step).

  Next, in a state where the peripheral surface of the grindstone 44 is in contact with the brush 38, the grindstone 44 is rotated around its axis by a rotating means (in FIG. 2, only the shaft 46 of the rotating means is shown) (here, a commutator). And the brush 38 is worn by a predetermined amount (the second step).

  Next, the external force is applied again to the sliding surface 39 of the brush 38, and the space at the original assembly position of the commutator 23 is expanded again. The grindstone 44 is removed in a state in which this space is expanded. In addition to this, the commutator 23 is disposed at the original assembly position in place of the grindstone 44. In this case, the peripheral surface 23A of the commutator 23 is brought into contact with the brush 38 (sliding surface 39 of the brush 38) (the third step).

  When each treatment as described above is applied to the sliding surface 39 of each brush 38, the sliding surface 39 of each brush 38 has a perfect circle centered on the axis of the commutator 23 in the cross section as shown in FIG. It will be located on the circumference. For this reason, the sliding surface 39 of each brush 38 contacts the peripheral surface 23A of the commutator 23 without rattling.

  Thus, the brush 38 is worn by the grindstone 44 having an outer diameter that is substantially the same as the outer diameter of the commutator 23, so the brush 38 is worn to the same extent as when the running process is performed. Therefore, the motor 10 with low noise and high rotation reliability can be manufactured.

  When the motor 10 is manufactured in this way, the sliding surface 39 of the brush 38 has already been worn to some extent at the time of assembly, so that the running processing time after assembly is shortened or the running processing itself is not necessary. . Therefore, the productivity of the motor 10 can be improved.

  In addition, since the running process time is shortened or the running process becomes unnecessary, the production cost of the motor 10 can be reduced.

  Further, as described above, the brush 38 (the sliding surface 39 of the brush 38) is worn by the grindstone 44. The roughness of the grindstone 44 is appropriately selected according to the hardness of the brush 38, so that the assembly assembly is performed. An optimum polished surface (sliding surface 39 of the brush 38) having a small sliding resistance (resistance generated between the brush 38 and the commutator 23) when driving the motor 10 later can be obtained.

  In the embodiment of the present invention, the grindstone 44 is used as the polishing member. However, instead of this, the brush 38 may be worn by sandpaper wound around the circumferential surface of the cylindrical roll. Even in the case where the brush 38 is worn by the sandpaper wound around the peripheral surface of the roll, the roughness of the sandpaper is appropriately selected according to the hardness of the brush 38 so that the motor 10 after assembly is driven when the motor 10 is driven. An optimum polished surface (sliding surface 39 of the brush 38) having a small resistance (resistance generated between the brush 38 and the commutator 23) can be obtained.

It is sectional drawing which shows the whole structure of the motor which concerns on embodiment of this invention. It is sectional drawing which shows the state which grind | polishes the brush with a grindstone. It is sectional drawing which looked at the positional relationship of a brush and the commutator of a motor from the axial direction of the commutator.

Explanation of symbols

  10..Motor (rotary electric machine), 23..Commutator, 23A..Peripheral surface (peripheral surface of commutator), 38 .... Brush, 44 ...

Claims (4)

A commutator, a plurality of brushes arranged in a state of being in pressure contact with the commutator in a circumferential direction of the commutator, and an end frame in which the plurality of brushes are assembled . In the manufacturing method of the rotating electrical machine,
A subassembly step of assembling the plurality of brushes to the end frame;
A polishing member that is cylindrical and has an outer diameter that is substantially the same as the outer diameter of the commutator is disposed in advance in the original assembly position of the commutator between the plurality of brushes, and the peripheral surface of the polishing member is A first step of contacting the brush;
A second step of rotating the polishing member to wear the brush a predetermined amount;
A third step of removing the polishing member, placing the commutator in the original assembly position instead of the polishing member, and bringing the peripheral surface of the commutator into contact with the brush;
The manufacturing method of the rotary electric machine characterized by the above-mentioned.
  The method for manufacturing a rotating electrical machine according to claim 1, wherein the polishing member is a grindstone. The polishing member is
A cylindrical roll,
Sandpaper wound around the circumferential surface of the roll;
The method for manufacturing a rotating electrical machine according to claim 1, wherein:   A rotating electrical machine manufactured by the method for manufacturing a rotating electrical machine according to any one of claims 1 to 3.

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