JP2016197930A - Brush motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brush motor capable of preventing reduction in the insulation resistance value at unspecific points within a motor by preventing brush-worn powder generated due to driving of the motor from scattering within the motor.SOLUTION: The brush motor has a brush holder 1 with a rib 10 formed so as to cover a commutator 5 attached to an outer periphery face at the rear end side of a shaft 3 and the outer periphery in a radial direction of a sliding contact portion 17 which in contact with a brush 6 in a sliding manner and which forms a pocket 11 for storing brush-worn powder which is guided by the rib 10. The brush-worn powder, which is generated due to contact in a sliding manner, is prevented from scattering within the motor by the rib 10. Thus, the insulation resistance value is prevented from being reduced at unspecific points within the brush motor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor with a brush for use in automobile electrical parts, industrial equipment and the like that cannot be easily replaced or serviced.

  Conventionally, a motor with a brush has been widely used as a power source for various products because it has a large starting torque and is inexpensive. The structure of this type of motor with a brush is disclosed in Patent Document 1, for example.

  As shown in FIG. 4, the brushed motor of Patent Document 1 includes a shaft 3, a bearing 4 </ b> C and a bearing 4 </ b> D that support the shaft 3, a commutator 5 attached to the outer peripheral surface of the shaft 3, Brush 6 slidably in contact with child 5, frame 2 holding brush 6, core 14 attached to the outer peripheral surface of shaft, winding 15 wound around core 14, and fixed disposed on the outer periphery of core 14 And a magnet 9 as a child.

  Further, according to the motor with a brush as in Patent Document 1, the pocket 11 is provided for collecting brush wear powder of the brush 6 generated by the brush 6 slidingly contacting the commutator 5 rotating integrally with the shaft 3. Therefore, by taking the brush powder from the brush 6 into the pocket 11 so as not to diffuse, a countermeasure against the problem that the insulation resistance value of the motor inner peripheral member is remarkably lowered has been taken.

  However, brush abrasion powder generated under the influence of the rotational speed of the rotor diffuses into the motor from the gap between the brush and the pocket and communicates with the motor, and accumulates in unspecified parts of the motor. There has been a problem that a problem occurs in which the insulation resistance value of the unspecified portion of the material significantly decreases.

Japanese Utility Model Publication No. 58-22865

  The present invention has been made to solve the above-mentioned problems, and it is possible to collect brush abrasion powder generated by driving the motor without diffusing inside the motor, preventing diffusion inside the motor, and unspecified parts. It is providing the motor with a brush which can suppress the fall of the insulation resistance value of this.

  A shaft, two bearings supporting the front end side and the rear end side of the shaft, a commutator positioned between the two bearings and attached to the outer peripheral surface of the shaft rear end side, and the commutator A brush that is in sliding contact; a brush spring that is in sliding contact with the commutator; a brush holder that holds the brush; and the outer periphery of the shaft that is located between the commutator and a shaft tip side bearing. The rotor provided on the surface, the stator disposed on the outer periphery of the rotor, the sliding contact portion of the brush and the outer periphery of the commutator, and the influence of the rotation of the commutator The present invention is characterized in that there are provided a rib and a pocket for storing the brush wear that prevent the brush wear powder generated while receiving the powder from diffusing in the radial direction.

  The brush wear powder diffusion suppression means includes a rib of the brush holder that covers a radially outer periphery of a commutator attached to the outer peripheral surface of the shaft rear end side and a sliding contact portion of the brush, The ribs of the brush holder are formed so as to narrow the outer periphery of the commutator and the brush sliding contact portion.

  The brush wear powder, the diffusion of which is suppressed by the ribs of the brush holder, is a box-shaped pocket that accumulates in a specific location, and this specific location is more effective by providing it in the direction of gravity in the motor mounting posture. Brush dust can be collected.

  The portion where the brush wear powder is to be stored is provided with a plurality of flat plate-like fins arranged at equal intervals to increase the holding power of the brush wear powder by increasing the surface area.

  Moreover, the surface roughness of the minute fins holding the brush wear powder can be intentionally roughened to make it easier to attach the brush wear powder.

  The intervals between the fins, which are equal intervals, may be set such that they adhere by utilizing the effects of static electricity, intermolecular force, etc. in consideration of the size and material of the brush wear powder.

  According to the present invention, as a specific structure of the motor with a brush, as described above, the brush holder is provided with ribs so as to narrow the outer periphery in the radial direction of the sliding contact portion between the brush and the commutator. Means were provided for suppressing the diffusion of brush wear powder generated by sliding contact.

  For this reason, brush abrasion powder is prevented from diffusing into the motor, and it is difficult for the phenomenon that the insulation resistance value decreases at unspecified parts, and the insulation resistance value inside the motor is kept high without decreasing for a long time. Can do.

  Further, the brush wear powder whose diffusion is suppressed by the structure is accumulated in a pocket in a gravity direction provided at a specific place, and is not diffused again by a plurality of flat fins holding the brush wear powder provided at the bottom of the pocket. A shape is also provided.

  For this reason, the re-diffusion of the brush wear powder that is about to diffuse again inside the motor due to external factors such as vibration is suppressed, and the insulation resistance value inside the motor is maintained for a long time even in harsh places where the operating environment is bad. The effect of being able to maintain high without reducing is obtained.

Sectional view of the brushed motor of the present invention The figure which shows the internal structure of the brush holder of the motor with a brush of this invention Enlarged view of a brush wear powder pocket and a plurality of fins provided in the pocket of the brushed motor of the present invention Sectional drawing of the motor with a brush with the storage pocket of the conventional brush abrasion powder.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a motor with a brush according to the present invention. The motor with a brush shown in FIG. 1 includes a shaft 3 in a cylindrical frame 2 sealed with a brush holder 1, bearings 4 </ b> A and 4 </ b> B indicating the shaft 3, and a commutator 5 attached to the outer peripheral surface of the shaft 3. The brush 6 is in sliding contact with the commutator 5, the rotor 8 is provided on the outer peripheral surface of the shaft 3, and the stator 9 is disposed on the outer periphery of the rotor 8. A rib 10 is provided on the sliding contact portion 17 of the brush 6 and the outer peripheral portion of the commutator 5 to guide the brush wear powder to be diffused inside the motor under the influence of the rotation of the rotor 8 to the pocket 11. ing.

  The shaft 3 is located on the central axis of the frame 2 and is disposed so that only the tip end portion thereof is exposed to the outside from the frame sealing end portion 2 </ b> A facing the brush holder 1. The bearing 4A and the bearing 4B are arranged one by one on the front end side and the rear end portion of the shaft 3, and the bearing 4A on the shaft front end side of the two bearings 4A and 4B is hermetically sealed against the brush holder 1. It is fitted and fixed in a recess 13A provided at the end 2A. The bearing 4B on the rear end side of the shaft is fixed by being fitted into a recess 13B provided in the brush holder 1. A thrust pressure in the axial direction of the thrust shaft is applied to the bearing 4B on the shaft rear end side by a thrust washer 16 inserted between the bearing 4B and the brush holder 1.

  The commutator 5 is formed of a metal material and an insulating material (resin mold), is attached to the outer peripheral surface of the rear end side of the shaft 3, and is urged by the brush spring 7 so as to always contact the outer peripheral surface of the commutator 5. .

  In the motor with a brush in FIG. 1, the brush holder 1 is fixed to the frame 2 by fitting the brush holder 1 to the frame opening end 2B and screwing it. Further, in the motor with a brush shown in the figure, the bearing 4B on the rear end side of the shaft is positioned in the recess 13B of the brush holder 1, and the brush 6 is held on the inner surface side of the brush holder 1.

  In this embodiment, the brush holder 1 is integrally formed of an insulating resin.

  The rotor 8 includes a core 14 made of a laminate of steel plates attached to the outer peripheral surface of the shaft 3 and a winding 15 wound around the core 14. On the other hand, the stator is composed of a magnet 9 and is fixed to a predetermined position on the inner surface of the frame 2.

  The brush motor of FIG. 1 configured as described above has a path from a power source (not shown) to the brush 6, the commutator 5, and then the winding 15 in the magnetic field formed by the magnet 9 serving as a stator. When the current flows, the shaft 3 rotates.

  Further, since the brush 6 slides on the commutator 5 that rotates integrally with the shaft 3, brush wear powder is generated.

  Since the brush wear powder diffuses in the radial direction under the influence of the rotating magnet 9 and the commutator 5, the brush wear powder tends to diffuse inside the motor.

  In the motor with a brush shown in FIG. 1, the rib 10 of the brush holder 1 is formed so as to cover the outer periphery of the commutator 5 and the sliding contact portion of the brush wear powder to be diffused during the operation of the motor. 10 suppresses the diffusion of the brush wear powder.

  As shown in FIG. 2, the rib 10 is partially provided with a pocket 11 which is a place for collecting brush wear powder. In FIG. 2, the rib 10 is removed so that the internal structure of the commutator 5 can be understood.

  In addition, a fin 12 for holding minute brush wear powder as shown in FIG. 3 is provided in the silent place, and has a function of preventing the brush wear powder from spreading again into the motor due to an external factor. .

  It is more effective to increase the holding power of the brush wear powder by designing or processing the surface of the brush wear powder holding rib to be rougher than the surface roughness of the brush holder 1.

  As described above, the brushed motor according to the present invention can be applied to automobile electrical components, industrial equipment, and the like, in which brush abrasion powder is unlikely to scatter inside the motor and the motor cannot be easily replaced or serviced.

DESCRIPTION OF SYMBOLS 1 Brush holder 2 Frame 2A Frame sealing end 2B Frame opening end 3 Shaft 4A, 4B, 4C, 4D Bearing 5 Commutator 6 Brush 7 Brush spring 8 Rotor 9 Magnet (stator)
10 Rib 11 Pocket 12 Fin 13A, 13B Recess 14 Core 15 Winding 16 Thrust Washer 17 Sliding Contact

Claims (4)

A shaft,
Two bearings for supporting the shaft front end side and the shaft rear end side of the shaft;
A commutator located between the two bearings and attached to the outer peripheral surface of the shaft on the rear end side of the shaft;
A brush in sliding contact with the commutator;
A brush spring that presses the brush against the commutator;
A brush holder for holding the brush;
A rotor that is located between the commutator and the shaft tip side bearing and is attached to the outer peripheral surface of the shaft;
A stator disposed on the outer periphery of the rotor;
Ribs that cover the sliding contact portion of the brush and the outer periphery of the commutator for suppressing the brush wear powder generated by the brush sliding on the commutator from diffusing in the radial direction of the shaft ,
A pocket for holding the brush wear powder,
The rib is formed so as to cover a radial outer periphery of the sliding contact portion of the commutator and the brush and to narrow an outer periphery of the commutator and the brush sliding contact portion, and the rib and the pocket are formed of the brush Molded integrally with the holder,
The brush motor according to claim 1, wherein the brush wear powder is guided and accumulated in the pocket by the rib. A plurality of fins arranged at equal intervals in a flat plate shape for increasing the surface area of the pocket portion are perpendicular to the bottom portion of the pocket so as to hold the brush wear powder accumulated in the pocket and prevent diffusion. The brush motor according to claim 1, wherein the brush motor is provided at a pocket bottom. The brush motor according to claim 1, wherein the plurality of fins have a rough surface so that the brush wear powder attached to the plurality of fins is prevented from diffusing again. 4. The motor with brush according to claim 1, wherein the brush holder is integrally formed by an insulating resin mold. 5.

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