JP2003274610A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain a temperature rise in a commutator and prevent infiltration of worn dust into a bearing. <P>SOLUTION: A motor 12 includes an armature 17 having a commutator 29, a shell case 14 having ball bearings 22a, 22b rotatably supporting the armature 17, and an end case 15. On one end of a rotor shaft 27, a disc member 34 is provided which is formed integrally with a reinforcing member 31 of a commutator 29 and protrudes in the radial direction. The disc member 34 is formed so as to be larger than an opening 23c in a bearing storage portion 23a storing the ball bearing 22a. The disc member 34 is brought near an edge 24 of the opening 23c. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor used for an electric blower or the like. 2. Description of the Related Art Conventionally, as a cooling structure for cooling an electric motor such as an electric blower used in an electric vacuum cleaner, for example, Japanese Patent Application Laid-Open No. 12-14077 discloses a disc integrated with a reinforcing member of a commutator. A technique is disclosed in which a member is formed by using a material having a high thermal conductivity so as to be exposed from the surface of a commutator, and a rotor of an electric motor is driven and rotated to cool the entire commutator. [0003] In the above publication, the outer diameter of the disk member is formed to be substantially the same size as the outer circumference of the commutator, and is larger than the outer circumference of the bearing that supports the rotor. It is formed small. When the electric motor is rotated, the commutator piece and the carbon brush are repeatedly energized and slid each time the motor is rotated, so that the commutator piece and the carbon brush are worn. May enter the inside of the bearing through the gap between the disk member and the bearing and adhere to grease or the like, which may adversely affect the life of the bearing. An object of the present invention is to provide an electric motor which suppresses a temperature rise of a commutator and prevents wear powder from entering a bearing. In order to achieve the above object, the present invention provides a disk member integrally formed with a reinforcing member of a commutator and protruding in a radial direction at one end of a rotor shaft. The disk member is made larger than the opening of the bearing storage portion in which the bearing is stored, and the disk member is brought close to the edge of the opening. An embodiment in which the electric motor of the present invention is applied to an electric blower will be described below with reference to the drawings. FIGS. 1 to 4 show an example in which the present invention is applied to an electric blower used for an electric vacuum cleaner. The electric blower 11 includes an electric motor 12 and a blower unit 13. The motor 12 is a commutator motor, which is a motor case composed of a body case 14 and an end case 15.
Stator 16, rotor 17, brush holders 18, 1
8 is attached. The body case 14 has an opening 19 at one end in the axial direction, and has a flange 20 around the opening 19. A ball bearing 22 serving as a bearing is provided at the center of a bottom wall 21 located at the other axial end of the body case 14.
a is formed in a cylindrical bearing storage portion 23a for storing a. The housing 23a is provided with a ball bearing 2
2a for accommodating the opening 2a.
an annular protruding portion 2 protruding from the inner surface of the bottom wall 21 at an edge portion of the bottom wall 21
4 are provided. On the peripheral surface near the bottom wall 21 of the body case 14, there are provided a plurality of outlets 25 as exhaust ports. The end case 15 has a through hole (not shown) formed in the center thereof, and a cylindrical bearing accommodating portion 23b for accommodating a ball bearing 22b as a bearing. The end case 15 is attached to the flange portion 20 across the opening 19 of the body case 14. The field 16 as a stator has a field coil (not shown) wound around a field core 26 and is held in the body case 14. As shown in FIG. 3, the armature 17 as a rotor has an armature core 28 and a commutator 29 as a commutator on a rotor shaft 27, and an armature coil 30 wound around the armature core 28 has a commutator. 29 is electrically connected to the outer peripheral portion. The field 16 in the body case 14 and the end case 15 and the armature 17 incorporated in the bearing accommodating portions 23a and 23b are provided with the rotor shaft 27 rotatably supported by ball bearings 22a and 22b. I have. The commutator 29 is press-fitted and fixed to the rotor shaft 27. As shown in FIG.
Is composed of a reinforcing member 31 made of a metal material, a resin tube 32 positioned on the outer periphery of the reinforcing member 31, and a plurality of commutator pieces 33 made of a conductive material fixed to the tube 32. The reinforcing member 31 and the plurality of commutator pieces 3
Reference numeral 3 denotes a resin cylinder 32 made of a thermosetting phenol resin material, which is joined by insert molding. The reinforcing member 31 is made of a metal having a high thermal conductivity, and has a disk-shaped disk member 34 at one end in the axial direction. The outer diameter of the disk member 34 is larger than the opening 23c of the bearing housing portion 23a, and specifically, is formed so as to protrude outward from the protrusion 24 provided at the edge of the opening 23c. One side surface 34a of the disk member 34 is provided on the inner surface of the bottom wall 21 so that abrasion powder such as a carbon brush and a commutator piece 33 does not enter the inside of the ball bearing 22a.
Specifically, it protrudes from the opening 23c of the bearing accommodating portion 23a and is close to the projecting end of the projecting portion 24. The bearing housing portion 23a and the ball bearing 22a
3, it is provided downstream of the commutator 29 in the flow direction of the wind. As shown in FIG. 1 and FIG.
The gap P between the disk member 34 and one side surface 34a is set to, for example, 0.5 mm in this embodiment. The size of the gap P depends on the rotation speed of the armature 17 and the like, and the disc member 34.
Needless to say, it can be set appropriately according to conditions such as the outer diameter of the above. When the protrusion 24 is not provided at the edge of the opening 23c, one side surface 34a of the disc member 34 is
A similar effect can be obtained by approaching the edge of the opening 23c of 3a. The brush holders 18, 18 are positioned in the circumferential direction of the body case 14, protrude partially from this circumferential surface, and are fixed with screws or the like. Inside the brush holders 18, 18, the carbon brushes 3 slidingly contacting the commutator 29 are provided.
5 and 35 are biased by a spring 36. The carbon brushes 35 contacting the commutator piece 33 and the commutator 29 are electrically connected to each other. The blower unit 13 has fixed guide blades 37 fixed to the outside of the end case 15 with screws or the like, and a centrifugal fan 38 as a centrifugal blade fixed to the rotor shaft 27 with a nut thereon. The fan cover 39 covers the centrifugal fan 38 and the fixed guide vanes 37 and is press-fitted and fixed to the flange 20 on the outer periphery of the case 14. The fan cover 39 has a suction port 40 for sucking outside air in the center of the front surface thereof, which faces the ventilation hole of the centrifugal fan 38. In such a configuration, when power is supplied to the electric motor 12, the armature 17 is rotated by the current flowing from the carbon brushes 35, 35 to the commutator 29 of the armature 17 and the magnetic force of the stator 16. At the same time, the centrifugal fan 38 fixed to the rotor shaft 27 is rotated to allow air to enter the motor case through the suction port 40, and is further provided at an axial end of a commutator 29 integral with the armature 17. The disk member 34 is also rotated at the same time. An air flow is generated by the centrifugal force of the disk member 34. The commutator 29 itself, the brush holder 18 and the carbon brushes 35, 3
5 is cooled, and the temperature rise can be suppressed. A reinforcing member 31 made of a metal material
And the disk-shaped disk member 34 are integrated, so that the volume of the metal material increases and the heat capacity can be increased. Since the disk member 34 has a larger diameter than the opening 23c of the bearing storage portion 23a and has a larger surface area than the commutator 29, the commutator 2 which is a heat source due to a heat radiation effect is provided.
9 can be suppressed. Thereby, thermal deterioration and destruction of the resin cylinder 32 can be prevented. The protruding portion 24 provided on the bottom wall 21 of the body case 14 and one side surface 34a of the disk member 34 are arranged close to each other. Since the disk member 34 covers the opening 23c through the small gap, it is possible to prevent the carbon brushes 35, 35 from entering the abrasion powder ball bearing 22a, and to remove the abrasion powder not in the opening 23c but in the radial direction. Because of the centrifugal force of the large-diameter disk-shaped disk member 34, the particles are blown off in the direction of the air outlet 25 and discharged from the motor case, so that the abrasion powder can be prevented from entering the ball bearing 22a. As described above, the reinforcing member 3 is
The provision of the circular member 34 integral with 1 prevents a temperature rise of the commutator 29 and the carbon brushes 35, 35, etc., provides a cooling effect, and prevents wear powder from entering the ball bearing 22a. Although the present invention has been described with respect to an electric motor applied to an electric vacuum cleaner, the present invention is not limited to this, and it is needless to say that this electric motor is employed in general devices such as home electric appliances. is there. As described above, according to the present invention,
It is possible to obtain an electric motor in which the temperature of the commutator is suppressed and wear powder is prevented from entering the bearing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing an electric blower according to an embodiment of the present invention in a partial cross section. FIG. 2 is an enlarged view of a portion A in FIG. FIG. 3 is a side view partially showing an armature included in the electric blower of FIG. 1; FIG. 4 is a side view showing a partly sectional view of a commutator provided in the armature shown in FIG. 3; [Description of Signs] 12 Electric motor 14 Body case (motor case) 15 End case (motor case) 16 Stator (field) 17 Rotor (armature) 22a, 22b Bearing (ball bearing) 23a, 23b Bearing storage section 23c Bearing storage Opening 24 of portion 23a Edge (projection) 27 Rotor shaft 29 Commutator (commutator) 31 Reinforcement member 32 Resin cylinder 33 Commutator piece 34 Disk member

Claims (1)

Claims: 1. An electric motor comprising a rotor having a commutator and a motor case having a bearing for rotatably supporting a rotor shaft of the rotor, wherein one end of the rotor shaft is provided. A disk member integrally formed with the reinforcing member of the commutator and protruding in the radial direction is provided, and the disk member is made larger than an opening of a bearing storage portion in which the bearing is stored, and the disk member is An electric motor, wherein the electric motor is located near an edge of the opening.