JP2013013266A - Ac commutator electric motor, motor-driven air blower and electric cleaner employing ac commutator electric motor - Google Patents

Abstract

When using an auxiliary brush to suppress commutation sparks of a small commutator motor, if the auxiliary brush is installed in the same direction as the main brush, the distance between the installation positions of the main brush and the auxiliary brush in the axial direction is narrow. It was difficult to use the brush holder for the main brush as it was.
In a commutator electric motor having an auxiliary brush, the auxiliary brush is provided in a forward direction with respect to the rotation direction of the commutator, and a point where the center line of the main brush and the commutator are in contact with each other is indicated by a. Is b, the center point of the commutator is c, and the angle ∠acb between the line ac and the line cb is θ1, the angle θ2 between the center line of the main brush and the center line of the auxiliary brush is By setting θ2> θ1, the brush holder for the auxiliary brush was fixed at a different location from the brush holder fixing portion for the main brush.
[Selection] Figure 1

Description

  The present invention relates to an AC commutator motor, an electric blower, and a vacuum cleaner that include a main carbon brush and an auxiliary carbon brush.

  An AC commutator motor (universal motor) used as a driving source for a vacuum cleaner includes an annular stator, a rotor disposed between magnetic poles of the stator, and an armature winding of the rotor. It is mainly composed of commutators and brushes that exchange power. This type of AC commutator motor for a vacuum cleaner is always required to have high output, small size, light weight, long brush life, and low vibration. The input is increased for higher output, and a nominal input of 1 kW is standard.

  High resistance brushes have been used to extend the life of brushes. In order to further increase the output, it is necessary to reduce brush electric loss having a large loss ratio in the loss configuration of the motor. In order to reduce brush electrical loss, it is desirable to use a low-resistance brush with low electrical resistance. However, a brush with low electrical resistance will reduce rectification performance and increase the generation of rectified sparks from the brush. Incurs a decline.

  Conventionally, in order to solve the above problem, in addition to the main brush for supplying electric power to the rotor, an auxiliary brush is provided in the advance direction with respect to the rotation direction, and a rectifying spark generated between the main brush and the commutator is A method of reducing the wear of the main brush by generating it between the auxiliary brush and the commutator instead of the main brush has been proposed (see Patent Document 1).

JP-A-7-336953

  In Patent Document 1, since the main brush and the auxiliary brush are both installed in the same direction perpendicular to the commutator surface, each brush holder for holding the main brush and the auxiliary brush is located at a very close position. Be placed. That is, there is a risk that it may be difficult to realize the components without interference with each other.

  Therefore, in order to apply the auxiliary brush to the conventional commutator motor having only the main brush, it is necessary to change the structure of the main brush device section that holds the main brush to a structure that can also hold the auxiliary brush. Furthermore, if the position of the current supply terminal for supplying current from the stator winding to the main brush overlaps the position of the auxiliary brush, it is necessary to change the position of the current supply terminal, so the auxiliary brush is easily attached. That can be difficult.

  Furthermore, since there is a risk that it may be difficult to share parts with a conventional commutator motor that does not use an auxiliary brush, there is a problem such as complicated parts management.

  An object of the present invention is to provide an AC commutator motor in which an auxiliary brush can be easily attached while maintaining the structure of a main brush device.

  In order to solve the above-described object, the present invention provides an auxiliary brush on the rear side with respect to the rotation direction of the commutator, and a point where the center line of the main brush and the commutator are in contact with each other, a. Is b, the center point of the commutator is c, and the angle ∠acb between the line ac and the line cb is θ1, the angle θ2 between the center line of the main brush and the center line of the auxiliary brush is By tilting the auxiliary brush so as to have an angle tilted backward with respect to the rotation direction of the commutator so that θ2> θ1, the auxiliary brush holder can be fixed in a place where it does not interfere with the main brush holder fixing portion. It is characterized by that.

  According to the present invention, the auxiliary brush can be easily used without changing the conventional motor structure, such as the structure of the conventional main brush unit and the position of the current supply terminal for supplying current from the stator winding to the main brush. It becomes possible to attach to.

  In addition, by tilting the auxiliary brush so that it is tilted backward with respect to the rotation direction, the force is distributed in the lateral direction, and the frictional force between the auxiliary brush and the commutator is reduced. The angular vibration (frictional vibration) of the auxiliary brush is also suppressed, and it is possible to obtain a sliding stability effect. As a result, the auxiliary brush can be easily installed and assisted by suppressing the rectifying sparks of the main brush without reducing the brush life. A commutator motor can be provided.

  In addition, during the commutator motor manufacturing process, the auxiliary brush is used only during “familiar operation” where commutation sparks are likely to occur, and it is easy to remove the auxiliary brush after the brush carbon film is formed on the commutator surface. It is possible to reduce the cost of the auxiliary brush.

The brush part enlarged view of the commutator motor concerning this invention. The brush apparatus part sectional drawing of the commutator motor concerning this invention. The figure which shows the structure of the electric blower using the alternating current commutator motor concerning this invention. It is a perspective view which shows the external appearance of a vacuum cleaner. It is a perspective view which shows the cleaner body of an electric vacuum cleaner.

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

  An embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a half cross section of an electric blower showing an embodiment of the present invention. 3A is a partial cross-sectional view seen from the rear, and FIG. 3B is a half cross-sectional view seen from the side. In FIG. 3B, the arrow indicates the flow direction of the fluid (for example, air). The electric blower 1 includes a commutator motor 2 that drives a centrifugal fan 70 at the rear, and a blower unit 3 that generates a high-speed airflow at the front. Therefore, in the electric blower 1, the side where the commutator motor 2 is present is the front, and the side where the blower unit 3 is present is the rear.

  As shown in FIG. 3, the commutator motor 2 is provided in the housing 100 and a stator 20 in which a field winding 22 is wound around a stator core 21 fixed on the inner peripheral side of a cylindrical housing 100. A rear housing side bearing 31, a front fan side bearing 32 provided on the end bracket, and a shaft 33 rotatably held by the housing side bearing 31 and the fan side bearing 32. The armature core 34 and the commutator 35 are fixed, and the armature winding 36 wound around the armature core 34 is electrically connected to the commutator 35 by mechanical contact with the rotor 30 connected to the commutator 35. For the main brush 41 for holding the auxiliary brush 51 attached to suppress the rectifying spark of the main brush 41, the main brush 41 and the auxiliary brush 51. Brush holder 42 and auxiliary brush holder 52 for auxiliary brush 51, main brush holder 42, main brush holder fixing portion 43 for main brush 41 for fixing auxiliary brush holder 52 to housing 100, auxiliary for auxiliary brush 51 The main brush device portion 40 for the main brush 41 and the auxiliary brush device portion 50 for the auxiliary brush 51 are configured by the brush holder fixing portion 53. The main brush device unit 40 includes a main brush 41, a main brush holder 42, and a main brush holder fixing unit 43. The auxiliary brush device unit 50 includes an auxiliary brush 51, an auxiliary brush holder 52, an auxiliary brush holder fixing unit 53, and the like. Consists of For example, the main brush 41 and the auxiliary brush 51 are made by compressing carbon powder mixed with copper or silver, and both are preferably made of the same material.

  The blower unit 3 is fixed to one end of the shaft 33 by a nut 60 and is provided on the outer periphery of the centrifugal fan 70, which is centrifugally rotated with the rotation of the shaft 33, and the air discharged from the centrifugal fan 70. A substantially annular diffuser 71 for reducing the flow velocity and recovering the pressure, and a return guide 73 for guiding the air flow into the commutator motor 2 and integrally formed with the diffuser 71 on the opposite surface of the bottom surface of the diffuser 71; The centrifugal fan 70, the diffuser 71, and the return guide 73 are configured to be surrounded by a cylindrical fan casing 102. The diffuser 71 and the return guide 73 are fixed to the fan casing 102 and do not rotate as the shaft 33 rotates. A through hole (suction port) for sucking air is formed at the center of the front surface of the fan casing 102. The commutator motor 2 and the blower unit 3 are connected so that air can communicate.

  When the electric blower 1 starts operation, the rotor 30 rotates, and the centrifugal fan 70 fixed coaxially with the rotor 30 also rotates. When the centrifugal fan 70 rotates, the airflow flows from the inlet portion of the centrifugal fan 70 through the diffuser 71 and the return guide 72 and passes through the inside of the commutator motor 2 as shown by the arrow in FIG. It is discharged from the back. Thus, the electric blower 1 obtains a high suction force while effectively cooling the loss on the electric motor side that occurs according to the work amount.

  Next, the configuration and operation of the brush device section, which is a feature of the present invention, will be described with reference to FIGS.

  Since the electric blower which shows the Example of this invention is the commutator motor 2 of 2 poles, the main brush apparatus part 40 and the auxiliary brush apparatus part 50 are each installed in the opposing position on the circumference of the commutator 35. It becomes composition.

  The main brush 41 is stored in a main brush holder 42, and the main brush holder 42 is fixed to the housing 100 by a main brush holder fixing portion 43. A lead wire 44 is connected to the end surface of the main brush 41 that is different from the end surface in contact with the commutator 35, and the lead wire 44 is attached to a terminal 45 and a stator 20 disposed in the main brush holder fixing portion 43. It is connected to the external electrode through the current supply terminal 25. Around the lead wire 44, there is a helical spring 46 for the main brush, and the main brush 41 is always in sliding contact with the commutator 35 due to the elasticity of the helical spring 46 for the main brush. On the outer periphery of the commutator 35, a plurality of commutator pieces 37 connected to the end portions of the armature winding 36 are arranged. The commutator pieces 37 are connected to other commutator pieces 37 adjacent to each other and an insulating portion 38. Is insulated by. The current supplied from the external electrode flows to the armature winding 36 via the current supply terminal 25, the terminal 45, the lead wire 44, the main brush 41, and the commutator 35, and the rotor 30 rotates.

  The auxiliary brush 51 is provided on the counter-rotating direction side of the main brush 41. The auxiliary brush 51 is stored in an auxiliary brush holder 52, and the auxiliary brush holder 52 is fixed to the housing 100 by an auxiliary brush holder fixing portion 53. An auxiliary brush helical spring 54 is disposed on the end surface of the auxiliary brush 51 that is different from the end surface in contact with the commutator 35. Like the main brush 41, the auxiliary brush 51 is always provided by the elasticity of the helical spring. It is in sliding contact with being pressed against 35. However, unlike the main brush 41, no electrical connection is made, and no current is supplied from the auxiliary brush 51 to the commutator 35. The auxiliary brush 51 is installed such that the auxiliary brush front edge 51a is positioned between the main brush front edge 41a and the main brush rear edge 41b, and the auxiliary brush rear edge 51b is positioned on the rear edge side of the main brush rear edge 41b. doing.

  Although the main brush 41 is arranged perpendicular to the surface in contact with the commutator 35, the auxiliary brush 51 is inclined rearward in the rotational direction from the vertical with respect to the surface in contact with the commutator 35, and the center line of the main brush 41 When the point where the commutator 35 is in contact is a, the point where the center line of the auxiliary brush 51 and the commutator 35 are in contact is b, and the center point of the commutator 35 is c, the angle ∠acb formed by the line ac and the line cb is θ1. Then, the angle θ2 formed by the center line of the main brush 41 and the center line of the auxiliary brush 51 is set so that θ2> θ1.

  The armature winding 36 that is short-circuited by the main brush 41 and undergoes rectification generates a large spark voltage depending on the rectification condition when the commutator piece 37 leaves the main brush trailing edge 41b, and the wear of the main brush 41 due to sparks is caused. growing. At this time, the generation of sparks from the main brush 41 can be reduced by the absorption of the spark voltage by the auxiliary brush 51 which is short-circuited by the auxiliary brush 51. As a result, the wear of the main brush 41 is reduced and the life is increased.

By the way, as described above, the commutator motor 2 is driven at a high rotational speed of 40,000 min ⁻¹ or more in order to achieve a reduction in size and weight. When the rotational speed increases, an increase in shaft vibration becomes a problem, but in order to suppress the vibration, the distance between the housing-side bearing 31 indicating the shaft 33 and the fan-side bearing 32 is made as small as possible so that the rotor 30 The natural vibration value is increased. For this reason, the distance between the bearings is set to be as small as possible. Correspondingly, the distance between the installation position of the main brush unit 40 and the position of the field winding 22 and the current supply terminal 25 is set to the insulation distance. We are as close as possible. Therefore, when the auxiliary brush 51 is attached to an electric blower that uses only the main brush 41 and does not use the auxiliary brush 51, if the auxiliary brush 51 is attached in the same direction as the main brush 41, an extra space is provided near the main brush device section 40. Therefore, the structure of the commutator motor 2 such as the position of the main brush holder 42, the main brush holder fixing portion 43, and the current supply terminal 25 provided on the stator 20 is increased, and the axial dimension is increased. It was.

  On the other hand, by fixing the auxiliary brush 51 not to the same direction as the main brush 41 but at a position inclined by a certain angle θ2, as in the present invention, the auxiliary brush 51 can be easily changed without changing the structure of the main brush device section 40. 51 can be added. Furthermore, it is well known that by tilting the brush in the rotation direction, friction between the brush and the commutator 35 is reduced and angular vibration of the brush can be suppressed, thereby improving the stability of the auxiliary brush 51.

  Further, since the structure of the main brush device section 40 is not changed, the auxiliary brush 51 can be easily removed. Thereby, in the manufacturing process, the carbon brush film is not generated on the surface of the commutator 35, and the auxiliary brush 51 is attached only during the “familiar operation” in which the commutation spark of the main brush 41 is likely to occur. After the rectification of the main brush 41 is stabilized, it is easy to remove the auxiliary brush 51, leading to cost reduction.

  The above auxiliary brush 51 has been shown to be tilted by θ2 rearward with respect to the rotational direction. However, the auxiliary brush 51 is tilted forward with respect to the rotational direction that is symmetric with respect to the central axis of the main brush 41. May be.

  As shown in FIG. 4, the electric vacuum cleaner 1001 includes a vacuum cleaner main body 1002, a hose portion 103, an operation tube 104 provided with a hand operation switch SW and the like, an extension tube 105 provided in a telescopic manner, The second suction tool 106 and the first suction tool 107 are provided.

  The vacuum cleaner main body 1002 includes the electric blower 1 (refer to FIG. 5, the same applies hereinafter) inside, and switches the strength of the operation of the electric blower 1 by operating the hand operation switch SW of the operation tube 104 or the first suction. A power brush (not shown) provided on the tool 107 can be turned on and off.

  Inside the hose portion 103, the operation pipe 104, the extension pipe 105, and the second suction tool 106 from the vacuum cleaner main body 1002 to the first suction tool 107, a ventilation path (not shown) is provided. The dust sucked by the generated suction force is sucked into the cleaner main body 1002 through the second suction tool 106, the extension pipe 105, the operation pipe 104, and the hose portion 103, and the dust collector 111 (see FIG. 5; the same applies hereinafter). ) Is collected.

  The outer shell of the cleaner body 1002 is covered with a lower case 201 and an upper case 202. The dust collector 111 is located on the front side of the cleaner body 1002 (the side on which the connection port 1002a is provided), and a handle 120 is integrally provided on the upper part of the upper case 202. In addition, a lid member 130 that can be opened and closed is provided in front of the handle 120 so that the upper portion of the dust collector 111 is closed by the lid member 130 so as to be opened and closed.

  As shown in FIG. 5, the cleaner body 1002 includes a tubular connection port 1002 a at the front end. A dust collector 111 that separates and collects the dust sucked from the connection port 1002a is provided on the front side of the cleaner body 1002, and a suction force that communicates with the dust collector 111 is provided on the rear side of the cleaner body 1002. An electric blower 1 is provided.

  A joint pipe (not shown) provided in the hose portion 103 is inserted and held in the connection port 1002a. A sealing member is provided inside the connection port 1002a, and the sealing member is configured to maintain airtightness between a joint pipe and an inlet pipe (not shown) provided on the dust collector 111 side. A caster 102c is provided on the lower surface of the front portion of the vacuum cleaner body 1002 (below the dust collector 111).

  The dust collector 111 includes a dust separator 111a and a dust container (dust container) 111b. The dust separation part 111a is a part that swirls the sucked air and separates the dust by a centrifugal separation action (cyclone method). The dust container 111b communicates with the dust separator 111a and includes therein a dust collection basket (not shown) that stores the dust separated by the dust separator 111a.

  The dust separation unit 111a and the dust storage unit 111b are arranged in the axial direction (front-rear inclination direction) of the dust collector 111, and are connected to each other in such a manner that their opposite axial ends are connected to each other so that air can flow. It is configured to be easily separable by a user operation. Among these, the dust separation part 111a is arrange | positioned in the front side of the cleaner body 1002, and the dust accommodating part 111b is arrange | positioned in the diagonally back side of the cleaner body 1002 rather than the dust separation part 111a. An opening (not shown) is provided at the front end of the dust separator 111a, and the opening is connected to the inlet pipe.

  The dust separation unit 111a includes an outer cylinder 111a1 and an inner cylinder 111a2 provided in the outer cylinder 111a1 and having a filter function. In the dust separator 111a, air flows from the outside of the inner cylinder 111a2 (inside of the outer cylinder 111a1) to the inside of the inner cylinder 111a2 through a through-hole (not shown). Garbage is separated between the outer cylinder 111a1 and the inner cylinder 111a2. In this case, although depending on the suction force, for example, dust having a weight of 1 yen or more is left in the outer cylinder 111a1 without being sucked up in the outer cylinder 111a1.

  The outer cylinder 111a1 and the inner cylinder 111a2 are provided so as to be easily separable by a user operation. As a result, when the garbage is thrown away, the outer cylinder 111a1 and the inner cylinder 111a2 are separated, whereby the dust accumulated in the outer cylinder 111a1 can be discharged, and the hair and lint caught in the through hole of the inner cylinder 111a2. Even if there is dust such as, it can be easily removed.

  Such a dust collector 111 is accommodated in the accommodation chamber opened at the front portion of the upper case 202 so as to be held by the side walls 243 from both the left and right sides.

  The side wall 243 is formed in an upwardly inclined shape from the front part to the center part of the upper case 202 so as to follow the dust collector 111, and the handle 120 is integrally fixed to the upper end part of the side wall 243.

  The commutator motor of the present invention can also be applied to a vacuum cleaner or a power tool.

DESCRIPTION OF SYMBOLS 1 Electric blower 2 Commutator motor 3 Blower part 20 Stator 21 Stator iron core 22 Field winding 25 Current supply terminal 30 Rotor 31 Housing side bearing 32 Fan side bearing 33 Shaft 34 Armature iron core 35 Commutator 36 Armature winding Wire 37 Commutator piece 38 Insulating part 40 Main brush device part 41 Main brush 41a Main brush leading edge 41b Main brush trailing edge 42 Main brush holder 43 Main brush holder fixing part 44 Lead wire 45 Terminal 46 Helical spring 50 for main brush Auxiliary Brush device 51 Auxiliary brush 51a Auxiliary brush leading edge 51b Auxiliary brush trailing edge 52 Auxiliary brush holder 53 Auxiliary brush holder fixing part 54 Auxiliary brush helical spring 60 Nut 70 Centrifugal fan 71 Diffuser 72 Return guide 100 Housing 101 End bracket 102 Fan casing

Claims (4)

  The AC commutator motor is provided with a main brush and an auxiliary brush, the auxiliary brush is provided in a forward direction with respect to the rotation direction of the commutator, a is a point where the center line of the main brush and the commutator are in contact with the center line of the auxiliary brush When the point where the child contacts is b and the center point of the commutator is c, the angle θ2 between the center line of the main brush and the auxiliary brush is θ2 when the angle ∠acb between the line ac and the line cb is θ1. , Θ2> θ1, and an AC commutator motor.   The AC commutator motor is provided with a main brush and an auxiliary brush, the auxiliary brush is provided in a forward direction with respect to the rotation direction of the commutator, a is a point where the center line of the main brush and the commutator are in contact with the center line of the auxiliary brush When the point where the child contacts is b and the center point of the commutator is c, the angle θ2 between the center line of the main brush and the auxiliary brush is θ2 when the angle ∠acb between the line ac and the line cb is θ1. , Θ2> θ1, and a brush holder that holds the auxiliary brush is removable.   An electric blower comprising the commutator electric motor according to claim 1 or 2 and a blower. A vacuum cleaner body having an electric blower and a dust collector, a hose with one end connected to the vacuum cleaner body, a hand operating part with one end connected to the other end of the hose, and one end other than the hand operating part In a vacuum cleaner comprising: an extension pipe connected to the end; and a suction tool connected to the other end of the extension pipe;
The electric blower includes an AC commutator motor and a blower. The AC commutator motor includes a main brush and an auxiliary brush, and the auxiliary brush is provided in a traveling direction with respect to the rotation direction of the commutator, and the center line of the main brush And a point where the commutator is in contact with a, b is a point where the commutator is in contact with the center line of the auxiliary brush, c is a center point of the commutator, and an angle ∠acb formed between the line ac and the line cb is θ1, An electric vacuum cleaner characterized in that an angle θ2 formed by the center line of the main brush and the center line of the auxiliary brush satisfies θ2> θ1.