JP2003264959A - Electric machinery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power blower in which insulation distance between a commutator shell and a motor frame is easily assured. <P>SOLUTION: A mold 57 which is an insulating member projecting from one end of a comutator shell 56 is made to radially project from the outer periphery of the commutator shell 56. The mold 57 is positioned between a bent part 37 of a motor frame 32 and the outer peripheral surface of the commutator shell 56. An insulation distance (D+E) is easily assured between the outer peripheral surface of the commutator shell 56 and the bent part 37 of the motor frame 32, with no additional separate insulating component. Leakage is prevented surely between the outer peripheral surface of the commutator shell 56 and the bent part 37 of the motor frame 32. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor for rotating a shaft via a commutator. 2. Description of the Related Art Conventionally, as an electric motor of this type, for example, a structure shown in FIGS. 5 and 6 has been known. [0003] The electric motor shown in Figs. 5 and 6 is an electric blower 1, and the electric blower 1 includes a motor frame 2 as a case body having conductivity. Inside the motor frame 2, a rotor shaft 3 as a shaft having a circular cross section is rotatably supported and mounted. A substantially cylindrical commutator 4 is attached between the rotor shaft 3 and the motor frame 2 near one end in the axial direction. The commutator 4 has a commutator shell 6 composed of a plurality of commutator bars 5 having a plurality of conductive pieces attached concentrically to the rotor shaft 3. . Further, between the commutator shell 6 and the rotor shaft 3, a molded part 7 as a resin part as an insulating member made of synthetic resin as an insulator is attached. The mold part 7 projects from one end in the axial direction of the commutator shell 6 to the outside of the commutator shell 6 and has an outer surface flush with the outer peripheral surface of the commutator shell 6. Further, as shown in FIG. 6, the outer diameter dimension B of the mold part 7 is equal to the outer diameter dimension C of the commutator shell 6 of the commutator 4.
Less than. The mold part 7 is located between the commutator shell 6 and the motor frame 2. Further, on the outer surface of the commutator shell 6,
A carbon brush 8 as a sliding contact for rotatingly driving the rotor shaft 3 is slidably contacted through the commutator shell 6. The carbon brush 8 is attached to the inner surface of the motor frame 2 facing the outer surface of the commutator shell 6. [0006] However, in the electric blower 1 described above, the motor frame 2 and the commutator shell 6 of the commutator 4 are close to each other in order to reduce the size. As shown in FIG.
Of the commutator shell 6 is short. For this reason, leakage may occur from the commutator shell 6 to the inner surface of the motor frame 2 beyond the insulation of the commutator 4 by the mold portion 7. Therefore, there is a problem that it is not easy to secure an insulation distance between the motor frame 2 and the commutator shell 6. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an electric motor capable of easily securing an insulation distance between a commutator piece and a case body. A motor according to the present invention has a shaft body rotatably provided on a case body, and a shaft body substantially coaxial with the shaft body and having a substantially cylindrical outer surface. A commutator piece having conductivity, and a commutator having an insulating member located between a case body that is one end in the axial direction of the commutator piece and protruding radially from an outer edge of the commutator piece; and And a sliding contact slidably contacting the outer surface of the commutator piece of the commutator. The outer surface of the commutator piece and the case body are formed by projecting the insulating member located between the case body that is one end in the axial direction of the commutator piece toward the radial direction from the outer edge of the commutator piece. Since the insulating member is located between
The insulation distance between the outer surface of these commutator pieces and the case body can be easily secured without adding other components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a vacuum cleaner according to one embodiment of the present invention will be described below with reference to FIGS. In FIG. 1 to FIG. 4, reference numeral 11 denotes a cleaner main body. The cleaner main body 11 is formed so as to be partitioned into an electric blower room (not shown) accommodating an electric blower 12 therein and an intake side of the electric blower room. A main body case 14 having a dust collection chamber (not shown) that opens the main body suction port 13 is provided. On the lower surface on the front side of the main body case 14, a turning wheel (not shown) is provided so as to be turnable and rotatable. A pair of driven rear wheels 15 as running wheels are rotatably provided on both rear side surfaces of the main body case 14, respectively. And
The main body case 14 can travel on the floor as a surface to be cleaned by each of the turning wheel and the driven rear wheel 15. The cleaner main body 11 has a flexible and elongated cylindrical hose main body 16 and is detachably connected to a main body suction port 13 provided at one end of the hose main body 16. Hose provided with a connecting pipe 17 to be connected and a hand operation unit 18 provided at the other end of the hose body 16 and serving as a gripping part of a user
19 is detachably connected. An elongate and contractible elongated cylindrical extension tube 21 is detachably connected to the distal end of the manual operation portion 18 of the hose 19. In addition, this extension pipe 21
At the end of the, the extension pipe 21 and hose
A floor brush 22 serving as a suction opening body having a suction opening (not shown) communicating with the main body suction opening 13 through the opening 19 on the lower surface is detachably connected. On the other hand, the electric blower 12 is provided with an electric motor 31 driven by electricity, as shown in FIGS.
The electric motor 31 has a substantially cylindrical motor frame 32 which is a body case as a case body. Inside the motor frame 32, a motor body 33 is housed. An opening 34 is formed in a front end face, which is one end of the motor frame 32 in the axial direction. Around the opening 34, a flange portion 35 having a substantially L-shaped cross section is formed so as to protrude toward the outer peripheral direction. A rear end face of the motor frame 32, which is the other end in the axial direction, is closed by a rear plate portion 36. The central part of the rear plate part 36 is
After bending and projecting in a concave arc shape toward the front side of 32 to form a bent portion 37 which is a curved portion as a throttle portion, and further projecting substantially rearward toward the rear, a bearing 38 is formed on the inner peripheral surface side.
Is provided via a bearing cap 39 as a bearing portion and a thrust spring 40. Here, the bent portion 37 of the rear plate portion 36 projects along the outside of the motor head portion 41 toward the intake side of the motor frame 32 along the axial direction of the motor head portion 41, and then has a cross section. It is curved by turning it into a substantially concave arc shape, and the rear plate portion
It is configured by being bent along the radial direction of 36. Therefore, the bent portion 36 ensures the strength of the motor head portion 41 with respect to the rear plate portion 36. In addition, the motor frame
On the peripheral surface near the rear of 32, there are multiple outlets as exhaust ports
An opening 42 is formed. At the front end of the motor frame 32, a long plate-shaped bridge portion 45 as an attachment body is provided.
Both ends in the longitudinal direction are attached to the flange portion 35 with screws 46 or the like so as to bridge in the radial direction of 32 and cover a part of the opening portion 34. At a substantially center of the bridge portion 45, a substantially disk-shaped mounting plate portion 47 is provided. In addition, a substantially cylindrical shape is formed at a substantially center of the mounting plate portion 47 so as to project in a substantially cylindrical shape toward the front and to fit and hold the bearing 38 on the inner peripheral side, and to open an insertion hole 48 at a substantially center of the front end. Is provided. The opening 34 of the motor frame 32 that is not covered by the bridge 45 and the circular opening (not shown) provided in the bridge 45 are ventilation holes. On the other hand, the motor body 33 is a motor frame.
A plurality of, for example, two first coils 52 are wound around a substantially tubular core 51 fixed to the iron plate 32 and laminated with iron plates, and a plurality of fixed poles are provided on the inner peripheral portion by energizing these first coils 52. That is, a stator 53 as a field which is a substantially cylindrical stator forming an N pole and an S pole and having an outer peripheral surface of a substantially quadrangular prism shape is provided. The motor body 33 is provided with a stator 53
The four corners of the core 51 abut on the motor frame 32 and are positioned and held in the motor frame 32. Further, the motor main body 33 is located substantially coaxially through the inner peripheral side of the stator 53 and both ends are rotatably supported by bearings 38 of the motor head 41 and the bridge 45, respectively. A rotor shaft 54 is provided as a shaft body to be provided. The motor head of the rotor shaft 54
In the vicinity of the end exposed from the stator 53 on the 41 side, a plurality of commutator bars 55 as a plurality of substantially plate-shaped commutator pieces are radially arranged in the circumferential direction and configured to be a cylindrical commutator. The shell 56 is inserted and disposed with the shafts substantially aligned. Further, between the commutator shell 56 and the rotor shaft 54, a molded portion 57 which is a resin portion as a substantially cylindrical insulating member formed of a synthetic resin having an insulating property is interposed, and a commutator 58 is provided. Is configured. Here, the commutator shell 56 of the commutator 58
Are conductive and are provided concentrically on the outer surface of the rotor shaft 54. Also, the mold portion 57 of the commutator 58
Is formed by pouring resin between the rotor shaft 54 and the commutator shell 56. In addition, this mold part
As shown in FIG. 1, the protrusion 57 projects from the rear end, which is one end in the axial direction, of the commutator shell 56 by a thickness D, and extends radially from the outer edge of the commutator shell 56. It protrudes in an annular shape by a protruding distance E which is a difference in diameter. That is, the outer diameter dimension F of the mold portion 57
Is larger than the outer diameter G of the commutator bar 55 of the commutator shell 56, as shown in FIG. Therefore, the molded portion 57 is formed by the bent portion 37 of the motor frame 32 and the commutator shell.
The motor frame 32 is located between
By increasing the creepage distance between the
The insulation distance between the bent portion 37 of the motor frame 32 and the outer surface of the commutator shell 56 is ensured. Further, a lead wire 62 is connected to the rotor shaft 54 at an inner peripheral side of the stator 53, and a lead wire 62 is appropriately connected to a substantially cylindrical laminated iron core 61 in which the rotor shaft 54 is fitted at the center. When a current is passed through the second coil 63, a plurality of movable poles facing the fixed pole of the stator 53, that is, an N pole and an S pole are formed at predetermined positions on the outer peripheral portion. An armature 64 as a child is provided integrally. A pair of terminal blocks 65 each formed in a substantially rectangular cylindrical shape by an insulating member are integrally mounted on the core 51 of the stator 53 so as to be positioned in the radial direction. In these terminal blocks 65, terminals 66 connected to a household commercial AC power supply (not shown), which is a power supply, are provided.
One of the terminals 66 has a pair of contact plate portions 68 that face each other so as to come into contact with the insertion opening 67 that is opened on the surface that is the end surface of the terminal block 65. Here, one of these contact plate portions 68 is curved toward the insertion opening 67 so as to be gradually separated from the other contact plate portion 68. The other of the terminals 66 is formed in a plate shape and bent substantially in an L shape. Also, the other terminal
A terminal block 65 is provided so that a connector provided at the end of a power line (not shown) connected to a household commercial AC power supply can be connected thereto.
The distal end protrudes from the insertion opening 67 in a tongue shape. A pair of brush mechanisms 71 are mounted on the motor frame 32 by screws 72 or the like, which are located substantially in the radial direction of the motor frame 32. Further, the motor body 33 is constituted by the brush mechanism 71, the stator 53, and the rotor shaft 54 provided with the armature 64 and the commutator 58. The brush mechanism 71 includes a carbon brush 73, which is a sliding contact at which one end surface in the longitudinal direction slides on the commutator 58 of the armature 64. The carbon brush 73 includes a brush holder 74 as a holder. Is held at The brush holder 74 has a conductive urging portion 75 (not shown), which has a bottomed rectangular tube shape and has a conductive property, into which the carbon brush 73 is fitted so as to be able to advance and retreat. Inside the holding urging portion 75, there is provided a coil spring or the like which urges the carbon brush 73 from the holding urging portion 75 in a direction in which the carbon brush 73 always advances to electrically connect the carbon brush 73 to the commutator 58. A biasing means 76 is provided. The brush retainer 74 has a connection terminal 77 that faces the surface of the terminal block 65 facing the insertion opening 67 and contacts the carbon brush 73.
Is provided. On the other hand, on the front side of the bridge portion 45, a diffuser 81 as a rectifying means is mounted and fixed with screws 82 or the like. In front of the diffuser 81, a fan 83 as a blower is disposed. This fan 83
It has heat resistance to heat generated by friction with air generated by rotation, and is made of, for example, an aluminum alloy in consideration of inertia, mass, and the like during rotation. The fan 83 has a disk-shaped lower plate 85 having a substantially disk shape and a hole 84 into which the rotor shaft 54 of the electric motor 31 is fitted at a substantially center. At a position opposed to the lower plate 85 with a predetermined gap therebetween, a ventilation hole 86 is formed at the center, and the upper plate 87 which has a substantially trumpet-shaped diameter toward the lower plate 85 side.
Are arranged. Further, between the lower plate 85 and the upper plate 87, a wall-shaped fan blade 89 that integrally defines a plurality of spiral intake air passages 88 is provided. The fan 83 has a rotor shaft 54 protruding from the electric motor 31 inserted into the insertion hole 84 of the lower plate 85, and the rotor shaft 54 is positioned on the back side of the lower plate 85 which is not opposed to the upper plate 87. A sleeve 91 for fitting the 54 is screwed into a threaded portion 92 formed at one end on the front side of the rotor shaft 54 at a position facing the upper plate 87 on the surface side of the lower plate 85. Both ends in the axial direction of the motor body 33 are fixed to the front end of the armature 64 of the motor body 33 by the hexagonal nut 93, with both ends in the axial direction being sandwiched via washers 94. Note that this fan 83 is
The rotation of the rotor shaft 54 causes the fan blade 89 to rotate in a spiral direction toward the center. On the other hand, the diffuser 81 is a motor frame.
It is attached and fixed to a mounting plate portion 47 of a bridge portion 45 so as to cover and close the opening portion of the 32. The diffuser 81 has a substantially triangular cutout (not shown)
A plurality of notches 101 are formed at regular intervals, and a substantially disc-shaped disk provided with a substantially cylindrical body 103 having a through hole 102 at the center thereof for fitting the mounting cylinder 49 of the bridge 45. It has a portion 104. An upstream rectifying plate 105 having a substantially vertical arc-shaped wall is provided on the upper surface of the disk portion 104 facing the fan 83 which is one surface of the disk portion 104. The upstream rectifying plate 105 is located near the periphery of the fan 83 at a distance slightly larger than the diameter of the fan 83 from the center. Also, this upstream rectifying plate 105
Are provided in a plane spiral shape in a direction opposite to the spiral direction of the fan blades 89 of the fan 83, and define a guide air passage 106 which is continuous with the notch 101. Further, on the lower surface facing the electric motor 31 side, which is the other surface of the disk portion 104, a plurality of downstream rectifying plates 107 having a substantially vertical arc wall shape are provided. A plurality of downstream rectifying plates 107 are provided in a plane spiral shape in a direction opposite to the upstream rectifying plate 105, and define a flowing air passage 108. On the other hand, a substantially cylindrical fan cover 111 is fitted around the outer periphery of the flange 35 of the motor frame 32. The fan cover 111 covers the fan 83. In the center of the front of the fan cover 111,
An intake port 112 facing the ventilation hole 86 of the fan 83 is formed. Further, a rear opening 113 is formed in the entire rear surface of the fan cover 111, and is formed in a substantially cylindrical shape. Next, the operation of the embodiment will be described. First, the electric blower 12 housed in the main body case 14 of the cleaner body 11 is driven and cleaned as needed. That is, a current flows through the first coil 52 of the stator 53 due to the voltage of the commercial AC power supply applied between the terminals 66, so that the core 51 is magnetized and the inner peripheral portion of the stator 53 has a different polarity. A plurality of fixed poles, N and S, are formed. At the same time, a carbon brush is
A current flows through the second coil 63 of the armature 64 via the commutator 73 and the commutator 58, and a plurality of movable poles having different polarities, ie, N pole and S pole, are formed at predetermined positions on the outer peripheral portion of the armature 64. Thereafter, the armature is repelled and attracted by the fixed pole of the stator 53 and the movable pole of the armature 64.
The rotor shaft 54 rotates together with 64, and the fan 83
Rotate in the spiral direction. Then, by the rotation of the fan 83, air is sucked from the air inlet 112 of the fan cover 111, and the fan 83
The air flows from the ventilation holes 86 of the fan 83 into the intake air passage 88 as suction air, and is blown outward to the outer peripheral side of the fan 83. Further, the suction air blown from the outer periphery of the fan 83 is guided by the upstream rectifying plate 105 of the opposed diffuser 81 and spirally flows through the guide air passage 106 to the outer peripheral side of the disk portion 104. It flows through the notch 101 to the back side of the disk part 104. The motor frame 32 of the electric motor 31 which is guided by the downstream rectifying plate 107 and flows through the flowing air passage 108, flows spirally toward the center of the diffuser 81, and is located on the back side of the diffuser 81. The air flows into the motor frame 32 through the ventilation opening, which is the opening 34 of the motor, and flows through the motor body 33 while cooling it, and is exhausted from the outlet 21. As described above, according to the above-described embodiment, the bent portion 37 is provided on the motor head portion 41 of the motor frame 32 of the general electric motor 31 in order to secure the strength of the motor head portion 41. Are formed. In addition, this bent part 37
Is close to the outer peripheral area of the commutator shell 56 of the commutator 58 because of the necessity of miniaturizing and standardizing the electric motor 31. Therefore, the outer peripheral edge of the molded portion 57 of the commutator 58 protruding from the rear end side in the axial direction of the commutator shell 56 is projected radially outward from the outer peripheral surface of the commutator shell 56. A mold portion 57 is located between the commutator shell 56 and the bent portion 37 of the motor frame 32. As a result, as shown in FIG. 1, the commutator does not need to be provided with another separate component having insulation between the commutator shell 56 and the bent portion 37 of the motor frame 32. Since the creepage distance between the shell 56 and the motor frame 32 increases, the insulation distance (D + E) between the outer peripheral surface of the commutator shell 56 and the bent portion 37 of the motor frame 32 is increased.
Can be secured more easily. Therefore, it is possible to more reliably prevent a leak from occurring between the outer peripheral surface of the commutator shell 56 and the bent portion 37 of the motor frame 32. Further, since the outer diameter F of the mold portion 57 of the commutator 58 is made larger than the outer diameter G of the commutator shell 56, the mold portion 57
Since the 57 projects in the circumferential direction, the mold portion 57 functions as a fan when the commutator 58 is driven to rotate.
Therefore, the motor body 33 can be cooled by the rotation of the mold portion 57 when the commutator 58 is rotationally driven, so that the temperature rise due to the driving of the electric motor 31 including the motor body 33 can be more efficiently prevented. it can. In the above-described embodiment, the electric blower 12 of the vacuum cleaner has been described. However, the present invention is not limited to the air, but may be any blower or pump for transferring any gas, and may be a structure for transferring a liquid such as water. Or a motor of a generator. For this reason, the fan 83 and the diffuser 81 are not limited to the above configuration, and may have any shape capable of transporting a fluid substance such as a gas or a liquid. Also, the mold portion 57 of the commutator 58 is interposed between the bent portion 37 of the motor frame 32 and the outer surface of the commutator shell 56 of the commutator 58, and The insulation distance between 37 and the outer peripheral surface of the commutator shell 56 is ensured, but the mold portion 57 is projected between the inner surface of a part of the motor frame 32 closest to the outer surface of the commutator shell 56. If the insulation distance between the motor frame 32 and the commutator shell 56 is ensured, the same function and effect as in the above-described embodiment can be obtained. According to the present invention, if the insulating member between the commutator piece and the case, which is one end in the axial direction, is made to protrude radially from the outer edge of the commutator piece. Since the insulating member is located between the outer surface of the commutator piece and the case body, the insulation distance between the outer surface of the commutator piece and the case body can be easily secured without adding other components.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a part of an embodiment of a motor of the present invention. FIG. 2 is a side view showing a commutator of the electric motor. FIG. 3 is a partially cutaway side view showing the electric motor. FIG. 4 is a perspective view showing a use state of the electric motor. FIG. 5 is a cross-sectional view showing a part of a conventional motor. FIG. 6 is a side view showing a commutator of the electric motor. [Description of References] 31 Electric motor 32 Motor frame 54 as a case body 54 Rotor shaft 55 as a shaft body Commutator bar 57 as a commutator piece Molded part as an insulating member 58 Commutator 73 Carbon brush as a sliding contact

Claims (1)

Claims: 1. A case body, a shaft body rotatably provided on the case body, and a conductive body having a substantially cylindrical outer surface provided with an axial center substantially coincident with the shaft body. And a commutator comprising an insulating member located between the commutator piece and the case body, which is one end of the commutator piece in the axial direction, and protruding radially from an outer edge of the commutator piece. An electric motor comprising: a sliding contact slidably contacting an outer surface of a commutator piece of the commutator.