JP2014230346A - Electric blower and electric cleaner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric blower with high durability and reliability.SOLUTION: The electric blower includes: a motor (not shown) which has a rotor (not shown) with a shaft (not shown) with a commutator (not shown) attached thereto and an armature winding (not shown) and a generally rectangular carbon brush 13 for supplying an electric power to the commutator (not shown) within a bracket (not shown); and an impeller (not shown) attached to the shaft for supplying cooling air inside the motor. The carbon brush 13 includes a slit 40 formed extending from a contact face with a commutator to the terminal face of the carbon brush 13, and the plane other than a plane contact with the commutator is processed with plating. A string-like conductor 28 which is embed in the terminal end of the carbon brush 13 for supplying the electric power and extends from the terminal face of the carbon brush 13 to the bottom of the slit 40. The temperature is prevented from rising by the slit 40 and an increased area of the plating, and thus the durability and the reliability of the electric blower are improved.

Description

  The present invention relates to an electric blower and a vacuum cleaner used for a vacuum cleaner and the like.

  As an electric blower for a conventional vacuum cleaner, there is one as shown in FIGS. 5 and 6 (see, for example, Patent Document 1). FIG. 5 is a half sectional view of a conventional electric blower described in Patent Document 1, and FIG. 6 is a structural view around a carbon brush of the electric blower.

  In FIG. 5, a conventional electric blower 1 includes a stator 2 in which a field winding (not shown) is applied to a field core 3, and an armature winding 8 on an armature core 7 that is passed through a shaft 6. The rotor 5 is provided with a commutator 9 coaxially arranged and rotatably fixed by bearings 10 provided at both ends of the shaft 6. The stator 2 and the rotor 5 are fixed to a bracket 12, and a motor 15 is formed by inserting a pair of carbon brushes 13 into the bracket 12 via a brush holder 14.

  The bracket 12 is provided with an exhaust port 19. Further, the shaft 6 is provided with an impeller 16, and a fan case 18 having an air inlet 24 is attached so as to cover them, so that the electric blower 1 is obtained. The commutator 9 includes a plurality of commutator pieces 20 and is fixed by a resin molding material 21 such as phenol. A connecting portion 25 for connecting the armature winding 8 is disposed on the rotor 5 side of the commutator piece 20.

  Next, the peripheral structure of the carbon brush 13 will be described with reference to FIG.

  The holder 26 made of a thermosetting resin is fixed to the bracket 12 with a screw fixed to the brush holder 14. The top plate 27 is connected to the carbon brush 13 via a string-like conductor 28 called a pigtail. A coil spring 29 is disposed between the top plate 27 and the carbon brush 13 so as to bias the carbon brush 13 toward the commutator 9.

  An electric conductor 30 formed of a material such as copper powder having a lower electric resistance than the carbon brush 13 is embedded in the center of the carbon brush 13 and a conductor 28 is embedded in the same part.

  The operation of the conventional electric blower 1 configured as described above will be described. When electric power is supplied, a current conducted through a field winding (not shown) passes through the top plate 27 and passes through the conductor 28. The electric conductor 30 is reached. Since the electrical conductor 30 has a smaller electrical resistance than the carbon brush 13, most of the current flows through the electrical conductor 30, reaches the tip of the carbon brush 13, is transmitted to the commutator 9, and the magnetic flux generated in the field core 3. A force is generated between the current passing through the armature winding 8 and the rotor 5 rotates. Next, when the rotor 5 rotates, the impeller 16 fixed to the shaft 6 of the rotor 5 rotates to increase the air in the impeller 16, and the increased air is guided to the electric motor 15.

  The airflow guided to the inside of the electric motor 15 is then discharged from the exhaust port 19 of the bracket 12 while cooling the rotor 5, the stator 2, and the carbon brush 13. Therefore, the resistance loss inside the carbon brush 13 is small, and the efficiency of the electric blower 1 can be improved.

JP-A-5-234654

  However, in the carbon brush 13 of the conventional electric blower 1 as described in the above-mentioned Patent Document 1, a hole is provided in the carbon brush 13 and the electric conductor 30 is embedded therein. The current concentrates on the part, and the temperature rise of the carbon brush 13 increases. In addition, the production process becomes complicated and expensive.

  The present invention solves the above-mentioned conventional problems, and suppresses the temperature rise of the carbon brush 13 with a simpler method, further suppresses sparks, and improves the durability and reliability. The purpose is to provide a vacuum cleaner.

  In order to solve the above-described conventional problems, an electric blower of the present invention includes a rotor in which an armature core, a commutator, and a bearing are inserted into a shaft and armature winding is provided, and a field magnet disposed on the outside thereof. An electric motor comprising a stator with a field winding on the core and a substantially rectangular carbon brush for supplying electric power to the commutator in a bracket, and cooling air supplied to the electric motor mounted on the shaft In the electric blower including the impeller, the carbon brush is provided with a space from a contact surface with the commutator toward a terminal end of the carbon brush and is plated on a surface other than the surface in contact with the commutator. And a string-like conductor for supplying electric power is embedded at the end of the carbon brush, and the conductor reaches from the end surface of the carbon brush to the bottom of the space. Shall in the space provided the carbon brush, in plating area increase, the temperature rise is suppressed, thereby contributing to the durability and reliability of the electric blower.

  Moreover, the vacuum cleaner of this invention is provided with the electric blower of any one of 1-4, and can provide the vacuum cleaner provided with high durability and reliability.

  Since the electric blower of the present invention can reduce the temperature rise and suppress the spark with the carbon brush, the electric blower realizes a highly durable and reliable electric blower, and the electric blower is mounted on the vacuum cleaner. Thus, it is possible to provide a highly durable and reliable vacuum cleaner.

One side sectional view of the electric blower in Embodiment 1 of the present invention (A) Partial sectional view around the carbon brush of the electric blower, (b) AA sectional view of FIG. 2 (a) (A) Partial sectional view around the carbon brush of the electric blower in Embodiment 2 of the present invention, (b) BB sectional view of FIG. 3 (a) (A) Partial sectional view around the carbon brush of the electric blower in Embodiment 3 of the present invention, (b) CC sectional view of FIG. 4 (a) A cross-sectional side view of a conventional electric blower Structural diagram around the carbon brush of the electric blower

1st invention inserts the armature core, the commutator, and the bearing in the shaft, and the rotor which gives armature winding, and the stator which is arrange | positioned on the outer side and gave field winding to the field core And an electric blower comprising: an electric motor that includes a substantially rectangular parallelepiped carbon brush that supplies electric power to the commutator; and an impeller that is attached to the shaft and supplies cooling air to the electric motor. The carbon brush has a space from the contact surface with the commutator toward the end of the carbon brush, and is plated on a surface other than the surface in contact with the commutator. A string-like conductor for supplying electric power is embedded, and the conductor reaches the bottom surface of the space from the end surface of the carbon brush, and is provided on the carbon brush. And while, by plating the area increase, the temperature rise is suppressed, thereby contributing to the durability and reliability of the electric blower.

  In the second invention, in particular, the space of the first invention is formed by a slit having an angle parallel to or perpendicular to the shaft, and an increase in temperature can be suppressed by the increase in the slit and the plating area. This contributes to improving the durability and reliability of the electric blower.

  In the third invention, in particular, the plating is applied only to the block on the traveling side of the rotation direction of the carbon brush divided into two substantially U-shapes by the slit of the second invention. As a result, temperature rise is suppressed and spark is suppressed, which contributes to improving the durability and reliability of the electric blower.

  In the fourth invention, in particular, the space of the first invention is formed by a hole having a substantially round cross section, and an increase in temperature is suppressed by an increase in the hole and the plating area, and the durability and reliability of the electric blower are reduced. It contributes to improvement of performance.

  The vacuum cleaner which concerns on 5th invention is provided with the electric blower of any one of 1st-4th, and can provide the vacuum cleaner provided with high durability and reliability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a half sectional view of the electric blower according to Embodiment 1 of the present invention, and FIG. 2A is a partial sectional view around the carbon brush of the electric blower (a view taken along arrow A in FIG. 1), FIG. FIG. 2B is a cross-sectional view taken along line AA in FIG. In addition, the same code | symbol is attached | subjected about the same component as the said conventional electric blower, and the description is abbreviate | omitted.

  A cage 26 made of a thermosetting resin for fixing the brush holder 14 is screwed to the bracket 12.

  The top plate 27 is connected to the carbon brush 13 via a string-like conductor 28 called a pigtail. The coil spring 29 is disposed between the top plate 27 and the carbon brush 13 and urges the carbon brush 13 toward the commutator 9.

  The carbon brush 13 is provided with a slit 40 that forms a space from the contact surface with the commutator 9 toward the end of the carbon brush 13 and parallel to the shaft 6 of the electric blower 1. The slit 40 may be installed at an angle with the shaft 6. The carbon brush 13 is plated with copper on all surfaces except the concave surface that contacts the commutator 9. The conductor 28 is embedded from the end of the carbon brush 13 and reaches the bottom surface of the slit 40.

  The operation and action of the electric blower 1 in the present embodiment configured as described above are as follows.

When electric power is supplied, the current conducted through the field winding passes through the top plate 27 and passes through the conductor 28.
Is transmitted from the carbon brush 13 to the commutator 9, a force is generated between the magnetic flux generated in the field core 3 and the current passing through the armature winding 8, and the rotor 5 rotates. Next, when the rotor 5 rotates, the impeller 16 fixed to the shaft 6 of the rotor 5 rotates to increase the air in the impeller 16, and the increased air is guided to the electric motor 15. The airflow guided to the inside of the electric motor 15 is then discharged from the exhaust port 19 of the bracket 12 while cooling the rotor 5, the stator 2, and the carbon brush 13.

  At this time, the current flowing from the conductor 28 reaches the surface of the carbon brush 13 and the inner surface of the slit 40. Since the surface of the carbon brush 13 is plated with copper, current flows in a concentrated manner in the plated portion having a smaller electrical resistance. This also applies to the plating surface inside the slit 40. Moreover, the presence of the slit 40 increases the area of the copper plating, reduces the current density, and suppresses resistance heat generation due to the current. Further, the slit 40 makes it easy for heat inside the carbon brush 13 to escape, increasing heat dissipation, and lowering the temperature of the carbon brush 13.

  As described above, according to the electric blower 1 in the present embodiment, the resistance loss inside the carbon brush 13 is small, the efficiency of the electric blower 1 can be improved, and the temperature rise in the carbon brush 13 can be reduced. And a highly reliable electric blower 1 can be provided.

(Embodiment 2)
Fig.3 (a) is a fragmentary sectional view around the carbon brush of the electric blower in Embodiment 2 of this invention, FIG.3 (b) is BB sectional drawing of Fig.3 (a). In addition, the same code | symbol is attached | subjected about the same component as the electric blower in the said Embodiment 1, and the description is abbreviate | omitted.

  In FIG. 3, in electric blower 1 in the present embodiment, brush holder 14 is fixed and cage 26 made of thermosetting resin is screwed to bracket 12. The top plate 27 is connected to the carbon brush 13 via a string-like conductor 28 called a pigtail. A coil spring 29 is disposed between the top plate 27 and the carbon brush 13 to urge the carbon brush 13 toward the commutator 9.

  The carbon brush 13 is provided with a slit 40 that forms a space from the contact surface with the commutator 9 toward the end of the carbon brush 13 and parallel to the shaft 6 of the electric blower 1. The slit 40 may be installed at an angle with the shaft 6.

  In particular, the carbon brush 13 of the electric blower 1 according to the present embodiment has a copper plating applied only to the rotational direction traveling side (shaded portion) of the commutator 9 among the two portions separated by the slit 40. The conductor 28 is embedded from the terminal end of the carbon brush 13 and touches the plating portion outside the carbon brush 13 and the plating portion on the bottom surface of the slit 40.

  The operation and action of the electric blower 1 in the present embodiment configured as described above are as follows.

  When electric power is supplied, the current conducted through the field winding passes through the top plate 27 and reaches the surface of the carbon brush 13 and the inner surface of the slit 40 via the conductor 28. Since the surface of the carbon brush 13 is plated with copper, current flows in a concentrated manner in the plated portion having a smaller electrical resistance. This also applies to the plating surface inside the slit 40. Moreover, the heat inside the carbon brush 13 is easily escaped by the slit 40, heat dissipation is increased, and the temperature of the carbon brush 13 is lowered.

  Furthermore, since the carbon brush 13 piece on the rotation progress side is plated with the slit 40 as a boundary, and the carbon brush piece on the downstream side of the rotation is not plated, most of the current has a small electric resistance. Flow through the brush piece on the side being plated. Therefore, the spark generated when the short-circuit current generated between the commutator 9 and the carbon brush 13 pieces on the downstream side of the rotation is cut off is small because the short-circuit current is small.

  Thus, according to the electric blower 1 in this Embodiment, there is little resistance loss inside the carbon brush 13, the efficiency of the electric blower 1 can be improved, and the temperature rise reduction in the carbon brush 13 can be aimed at. Furthermore, since the spark can be suppressed, the electric blower 1 having high durability and high reliability can be provided.

(Embodiment 3)
FIG. 4A is a partial cross-sectional view around the carbon brush of the electric blower according to Embodiment 3 of the present invention, and FIG. 4B is a cross-sectional view taken along the line CC in FIG. In addition, the same code | symbol is attached | subjected about the same component as the electric blower in the said embodiment, and the description is abbreviate | omitted.

  In FIG. 4, in electric blower 1 according to the present embodiment, cage 26 made of a thermosetting resin that fixes brush holder 14 is screwed to bracket 12.

  The top plate 27 is connected to the carbon brush 13 via a string-like conductor 28 called a pigtail. A coil spring 29 is disposed between the top plate 27 and the carbon brush 13 to urge the carbon brush 13 toward the commutator 9.

  In particular, in the present embodiment, the carbon brush 13 is provided with a round hole 41 having a substantially circular cross section that forms a space from the contact surface with the commutator 9 toward the end of the carbon brush 13. The conductor 28 is embedded from the end of the carbon brush 13 and touches the plating part on the outside of the carbon brush 13 and the plating part on the bottom surface of the round hole 41.

  The operation and action of the electric blower 1 in the present embodiment configured as described above are as follows.

  When electric power is supplied, the current conducted through the field winding passes through the top plate 27 and reaches the surface of the carbon brush 13 and the inner surface of the round hole 41 via the conductor 28. Since the surface of the carbon brush 13 is plated with copper, current flows in a concentrated manner in the plated portion having a smaller electrical resistance. This also applies to the plating surface inside the round hole 41. Moreover, the heat inside the carbon brush 13 is easily escaped by the round hole 41, heat dissipation is increased, and the temperature of the carbon brush 13 is lowered. Furthermore, the strength of the carbon brush 13 is improved as compared with the slit 40 in the above embodiment.

  Thus, according to the electric blower 1 in the present embodiment, while maintaining the strength of the carbon brush 13, there is little resistance loss inside the carbon brush 13, the efficiency of the electric blower 1 can be improved, and the carbon brush 13 Therefore, the electric blower 1 having high durability and reliability can be provided.

  Needless to say, if any one of the electric blowers 1 described in the first to third embodiments is mounted on a vacuum cleaner, a highly durable and reliable vacuum cleaner can be provided.

As described above, since the electric blower according to the present invention can improve durability, reliability, and safety, it is not limited to a vacuum cleaner, and various household electrical appliances and industrial equipment using an electric blower. It can be applied to a wide range of applications.

DESCRIPTION OF SYMBOLS 1 Electric blower 2 Stator 3 Field core 5 Rotor 6 Shaft 7 Armature core 8 Armature winding 9 Commutator 10 Bearing 12 Bracket 13 Carbon brush 14 Brush holder 15 Electric motor 16 Impeller 18 Fan case 19 Exhaust port 20 Commutator piece 21 Resin molding material 24 Air inlet 25 Connection portion 26 Cage 27 Top plate 28 Conductor 29 Coil spring 30 Electric conductor 40 Slit (space)
41 Round hole (space)

Claims (5)

A rotor in which an armature core, a commutator, and a bearing are inserted into a shaft and armature winding is provided, a stator that is disposed outside the field core and that is provided with field winding on a field core, and the commutator An electric blower comprising: an electric motor including a substantially rectangular parallelepiped carbon brush for supplying electric power in a bracket; and an impeller attached to the shaft for supplying cooling air into the electric motor. A space is provided from the contact surface with the commutator toward the end of the carbon brush, and a surface other than the surface in contact with the commutator is plated to supply power to the end of the carbon brush. The electric blower is characterized in that the conductor reaches the bottom surface of the space from the end surface of the carbon brush. The electric blower according to claim 1, wherein the space is formed by a slit having an angle other than vertical or parallel to the shaft. The electric blower according to claim 2, wherein plating is applied only to a block on a traveling side in a rotation direction of the carbon brush divided into two substantially U-shaped by a slit. The electric blower according to claim 1, wherein the space is formed by a hole having a substantially round cross section. The vacuum cleaner provided with the electric blower of any one of Claims 1-4.

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