JP2013024134A - Electric blower and vacuum cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric blower capable of reducing pressure loss ventilation and miniaturizing by effectively cooling a brushless motor.SOLUTION: In the electric blower, an airflow discharged from an impeller and guided to an air guide is flowed to a ventilation passage formed between an outer cylinder and a frame, and a plurality of holes wherein the diameter of each hole is set up to be a length or below of a core in a rotary axis direction against the rotary axis direction are arranged at a position come in contact with the core of a stator on an outer periphery of the frame. Thus, heat radiation via no frame can be performed by making the air directly come in contact with the core by means of the holes, and a heat radiation area can be increased with an uneven shape. Further, a part of a laminar flow of the air flowing along the frame gets a turbulent flow generates by the holes, and an air come in contact with the frame and the core can be increased. Consequently, a compact cooling structure capable of restraining pressure loss can be attained since the heat radiation can be effectively performed with such the structure.

Description

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

  Most of conventional electric blower motors used in household vacuum cleaners use universal motors. In recent years, those having a stronger suction force and those that are smaller and lighter in weight are required for usability. In view of this, an electric blower using a brushless motor has been proposed in order to improve the suction work rate by making it rotate at a higher speed, and to be small and light (see, for example, Patent Document 1).

  In Patent Document 1, as shown in FIG. 5, an impeller 109 attached to the tip of a rotating shaft 102 includes a rotor 101 attached to the rotating shaft 102, a stator core 104, and a coil 103. Is rotated by a brushless motor including a frame 105 including a frame 105, a bearing 107 and a bearing 108 that rotatably connect the frame 105 and the rotating shaft 102. The air guide 110 arranged on the outer periphery of the impeller 109 having a plurality of blades recovers the pressure of the air blown by the rotation of the impeller 109 and bends greatly inward by the air guide 110 to enter the inside of the brushless motor. It flows and cools the stator and the rotor 101.

  When a brushless motor is used, the main heat generating part of the motor is the armature / stator and commutator of the universal motor. A proposal has been made to reduce pressure loss caused by blowing air by flowing air (see, for example, Patent Document 2). In Patent Document 2, as shown in FIG. 6, an impeller 109 attached to the tip of a rotating shaft 102 includes a rotor 101 attached to the rotating shaft 102, a stator core 104, and a coil 103. Is rotated by a brushless motor including a frame 105 including a frame 105, a bearing 107 and a bearing 108 that rotatably connect the frame 105 and the rotating shaft 102.

  The air guide 110 arranged on the outer periphery of the impeller 109 having a plurality of blades recovers the pressure of the air blown by the rotation of the impeller 109 to the ventilation path 114 formed between the outer cylinder 113 and the frame 105. And flow. The main place of heat generated by the brushless motor is the coil 103, but the heat is radiated from the coil 103 to the air in the ventilation path 114 via the stator core 104 and the frame 105.

JP 2003-135320 A JP-A-11-336696

  However, in the conventional configuration in which air is blown into the motor for cooling, it is necessary to bend the air largely from the discharge port of the air guide and guide it into the motor, so that a large pressure loss of the air blow occurs. Furthermore, since the gap inside the motor is small, further pressure loss occurs to pass through this. On the other hand, in the configuration in which air flows along the outer periphery of the motor frame, the air pressure loss in the ventilation path is kept low, but the heat generated in the coil is dissipated through the core frame, so it is enough to make it smaller. Cooling is not possible. Therefore, there is a problem that the size reduction is restricted due to poor heat dissipation efficiency.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an electric blower that reduces the pressure loss of air blowing and efficiently cools a brushless motor to reduce the size.

  In order to solve the conventional problems, an electric blower of the present invention holds a rotor having a rotating shaft, a stator having a plurality of coils, and a bearing that includes the stator and supports the rotating shaft. A brushless motor configured with a frame, and having a plurality of blades, including an impeller fixed to a rotating shaft, an air guide disposed on an outer periphery of the impeller, and including the impeller and the air guide A fan case having an air inlet at the center and fixed to at least a part of the frame or the air guide; an outer cylinder connecting portion connected to the fan case; and an outer cylinder provided outside the frame; A passage formed between the outer cylinder and the frame. The passage is formed by the impeller and flows the air guided to the air guide along the outer periphery of the frame. Configured, those provided a plurality of holes and less than the length of the rotation axis direction of the core with respect to the rotation axis direction in the core is in contact position of the stator on the outer periphery of the frame.

  As a result, heat can be radiated without interposing the frame when air directly contacts the core through the hole, and the heat radiation area is increased by the uneven shape. Further, a part of the laminar flow of the air flowing along the frame generates a turbulent flow due to the holes, and the air contacting the frame and the core increases. Since these can efficiently dissipate heat, it is possible to realize a cooling structure that is small and suppresses pressure loss.

  The electric blower of the present invention can be cooled efficiently because the amount of heat transmitted to the air increases while suppressing the pressure loss of the air flowing around the outer periphery of the frame, and thus can be reduced in size while suppressing a decrease in the efficiency of the blowing.

The partially broken side view of the electric blower in Embodiment 1 of this invention The top view which shows the air guide and impeller part of the electric blower The partially broken side view of the electric blower in Embodiment 2 of this invention Sectional drawing of the brushless motor part in Embodiment 2 of this invention Partially cutaway side view of an electric blower that cools air through a conventional motor Partially broken side view of a conventional electric blower that cools air through the outer circumference of a conventional motor

  A first invention includes a brushless motor including a rotor having a rotating shaft, a stator having a plurality of coils, and a frame that holds a bearing that includes the stator and supports the rotating shaft. The impeller having a plurality of blades, fixed to the rotating shaft, the air guide disposed on the outer periphery of the impeller, the impeller and the air guide are included, and the air inlet is disposed at the center, at least A fan case fixed to a part of the frame or the air guide; an outer cylinder portion including an outer cylinder connection portion connected to the fan case and an outer cylinder provided outside the frame; and the impeller And a passage for flowing the air guided to the air guide along the outer periphery of the frame is formed between the outer cylinder and the frame, and the stator is disposed on the outer periphery of the frame. Core those provided a plurality of said rotating axis direction with respect to the following length of the rotation axis direction of the core hole is in contact position.

With this configuration, heat can be dissipated without a frame when air directly contacts the core through the hole, and the heat dissipation area increases due to the uneven shape. Further, a part of the laminar flow of the air flowing along the frame generates a turbulent flow due to the holes, and the air contacting the frame and the core increases. Since these can efficiently dissipate heat, it is possible to realize a cooling structure that is small and suppresses pressure loss.

  In the second invention, in particular, the shape of the hole on the outer periphery of the frame according to the first invention is a long hole in a direction along the flow of the swirling airflow from the air guide. Since a large number of unobstructed portions can be taken, the surface area of heat radiation can be increased to improve the heat radiation performance and the swirling airflow is not obstructed, that is, pressure loss can be suppressed. Therefore, efficient cooling can be realized while further suppressing an increase in pressure loss.

  In the third aspect of the invention, in particular, since the holes on the outer periphery of the frame of the first aspect of the invention are arranged in a staggered manner, the holes contributing to cooling are uniformly arranged, so that uneven cooling can be achieved. Efficient cooling can be realized.

  According to a fourth aspect of the present invention, in particular, the fin has a fin formed by cutting and bending the hole on the outer periphery of the frame of the first aspect of the invention, and the fin is in a direction along the flow of the swirling airflow from the air guide With this configuration, the heat radiation area of the frame is remarkably increased and the hindrance of the swirling airflow flowing through the ventilation path can be minimized, so that efficient cooling can be realized while suppressing an increase in pressure loss.

  In the fifth aspect of the invention, in particular, the stator core of the first aspect of the invention is provided with a groove on the outer peripheral surface of the core that is an extension line in the radial direction of the teeth protruding toward the inner diameter side of the core, and the groove rotates. Since it is configured to communicate with the end faces on both sides of the core in the axial direction, it is brushless through the groove provided on the outer peripheral surface of the core by the flow of air entering the groove from the hole provided in the frame or the rotation of the impeller Since the core is directly cooled by the flow of air guided from the inside of the motor through the bearing gap to the outer periphery of the impeller, efficient cooling can be realized.

  In the sixth aspect of the invention, in particular, since the hole on the outer periphery of the frame and the groove on the outer periphery of the core are aligned with each other, air flows from the hole to the groove on the outer periphery of the core. Can be cooled directly, so that efficient cooling can be realized.

  In the seventh aspect of the invention, in particular, by mounting the electric blower according to any one of the first to sixth aspects of the invention on a vacuum cleaner, a vacuum cleaner that is small and lightweight and has a high suction work rate can be realized.

  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: shows the partially broken front view of the electric blower in the 1st Embodiment of this invention.
In FIG. 1, reference numeral 1 denotes a rotor, and the rotor 1 is arranged around a rotating shaft 2. A stator having a coil 3 and a stator core 4 is arranged on the outer peripheral side of the rotor 1. The core 4 is fixed to the frame 5, and the frame 5 and the bracket 6 connected to the frame 5 hold the bearing 7 and the bearing 8, and rotatably support the rotating shaft 2. An impeller 9 is connected to the tip of the rotary shaft 2, an air guide 10 is arranged on the outer periphery of the impeller 9, and it is configured by a plurality of independent diffusers. The air discharged from the impeller 9 is gradually decelerated to recover pressure. It is carried out.

The fan case 11 has an air inlet for allowing air to flow into the central portion, and a resin ring 12 is disposed at the air inlet, thereby minimizing a gap with the impeller 9 and preventing air leakage. . An outer cylinder 13 connected to the air guide 10 is provided on the outer peripheral side of the frame 5, and a ventilation path 14 is formed between the outer cylinder 13 and the frame 5. The airflow discharged from the impeller 9 is guided to the ventilation path 14 through the air guide 10. A plurality of holes 15 are provided in the frame 5 on the outer peripheral side of the stator core 4.

  Since the hole 15 is smaller than the length of the stator core 4 in the rotation axis direction, the frame rigidity and dimensional accuracy can be secured when the stator core 4 and the frame 5 are fixed by shrinkage. Of the airflow passing through the ventilation path 14, part of the airflow flowing along the frame 5 changes from laminar flow to turbulent flow due to the uneven shape due to the holes 15. Thereby, since the airflow which contacts the flame | frame 5 or the core 4 of a stator increases, since cooling efficiency improves and the airflow which flows through the ventilation path 14 is not blocked | interrupted largely, the big increase in pressure loss can be suppressed.

FIG. 2 is a plan view showing an air guide / impeller portion of the electric blower according to Embodiment 1 of the present invention.
In FIG. 2, the airflow discharged toward the outer periphery from the impeller 9 having a plurality of blades attached to the rotating shaft 2 is gradually recovered by the air guide 10, and then the airflow inside the outer cylinder 13. It is sent to the road 14 as a swirling airflow. Therefore, if the hole 15 of the frame 5 has a longitudinal shape along the direction of the swirling airflow, for example, a shape such as an oval square or an ellipse, the swirling airflow is lost against the increase in the heat radiation area due to the step of the hole. Since the ratio of the step in the direction perpendicular to the easy swirling airflow can be reduced, the cooling effect can be enhanced more than the increase in pressure loss.
Furthermore, by arranging the holes 15 in a zigzag pattern along the direction of the swirling airflow, it becomes easy to cool uniformly, so that the cooling efficiency can be increased.

Further, the pressure loss can be reduced by making the inner corner of the outer cylinder 13 on the outer peripheral side of the outer cylinder 13 into a curved surface so that the airflow passing through the air guide 10 is gradually changed.
Furthermore, pressure loss can be reduced by forming the shape in which the angle is a curve and gradually widens in the space of the air discharge portion formed by the air guide 10 and the outer cylinder 13.

  In addition, in the space of the air discharge portion formed by the air guide 10 and the outer cylinder 13, the flow direction of the air guide 10 is set to the direction intersecting the frame 5, so that a large amount of air flow contacts the frame 5. And can be cooled efficiently.

(Embodiment 2)
FIG. 3: shows the partially broken front view of the electric blower in the 2nd Embodiment of this invention.
In FIG. 3, reference numeral 1 denotes a rotor, and the rotor 1 is arranged around a rotating shaft 2. A stator having a coil 3 and a stator core 4 is arranged on the outer peripheral side of the rotor 1. The core 4 is fixed to the frame 5, and the frame 5 and the bracket 6 connected to the frame 5 hold the bearing 7 and the bearing 8, and rotatably support the rotating shaft 2. An impeller 9 is connected to the tip of the rotary shaft 2, an air guide 10 is arranged on the outer periphery of the impeller 9, and it is configured by a plurality of independent diffusers. The air discharged from the impeller 9 is gradually decelerated to recover pressure. It is carried out.

  The fan case 11 has an air inlet for allowing air to flow into the central portion, and a resin ring 12 is disposed at the air inlet, thereby minimizing a gap with the impeller 9 and preventing air leakage. . An outer cylinder 13 connected to the air guide 10 is provided on the outer peripheral side of the frame 5, a sound absorbing material 17 is provided inside the outer cylinder 13, and a ventilation path is provided between the outer cylinder 13, the sound absorbing material 17, and the frame 5. 14 is formed. Since the sound absorbing material 17 has a much larger pressure loss than the ventilation path 14, air hardly passes through the sound absorbing material 17.

The airflow discharged from the impeller 9 is discharged as a swirling airflow through the air guide 10 to the ventilation path 14 as in FIG. 2 of the first embodiment.
A plurality of holes 15 are provided in the frame 5 on the outer peripheral side of the stator core 4, and the holes 15 cut and raise the frame 5 and thus have fins 16. Further, since the hole 15 is smaller than the length of the stator core 4 in the rotation axis direction, the frame rigidity and dimensional accuracy can be secured when the stator core 4 and the frame 5 are fixed by shrinkage. Since the holes 15 and the fins 16 are arranged in a staggered manner in the direction along the swirling airflow passing through the ventilation path 14, the fins 16 perform a cooling function without interfering with the swirling airflow, and thus efficiently cool while suppressing pressure loss. be able to.

  Furthermore, since it becomes easy to cool uniformly by the staggered arrangement, the cooling efficiency can be increased. On the other hand, since the ventilation path 14 is guided by the sound absorbing material 17 so as to collect the airflow toward the frame 5, the amount of air contributing to cooling can be increased along with the attenuation of noise.

  Further, by providing the ventilation hole 19 and the ventilation hole 20 at a position where the coil end of the coil 3 of the stator core 4 is exposed on the frame 5, the airflow directly contacts the coil 3, so that the cooling can be performed more efficiently. Is possible. Since a part of the airflow passing through the ventilation hole 19 and the ventilation hole 20 passes through the inside of the motor, the cooling effect can be further enhanced.

  FIG. 4 is a cross-sectional view of the brushless motor unit according to Embodiment 2 of the present invention. In FIG. 4, a rotor 1 is rotatably mounted on a rotating shaft 2, and a stator having a coil 3 and a stator core 4 is included in a frame 5 on the outer periphery thereof. The core 4 of the stator has teeth 21 protruding toward the inner diameter side, and the coil 3 is wound around the teeth 21. A hole 15 is provided in the frame 5.

  A groove 18 is provided on the outer peripheral surface of the stator core 4 that is an extension line in the radial direction of the teeth 21, and the groove 18 is configured to communicate with both end faces of the stator core 4 in the rotation axis direction. It arrange | positions so that the position of the hole 15 of the flame | frame 5 may be met. The groove 18 does not disturb the magnetic flux flowing inside the stator core 4. Since the groove 18 is aligned with the position of the hole 15, the heat radiation area in the hole 15 is increased, and the cooling efficiency can be increased by passing a part of the airflow through the groove 18.

  As described above, the electric blower according to the present invention can be efficiently cooled because the amount of heat transmitted to the air is increased while suppressing the pressure loss of the air flowing around the outer periphery of the frame, and therefore, the electric blower can be reduced in size while suppressing the decrease in the efficiency of the blowing. Therefore, it is possible to realize a small and light electric blower with high blowing efficiency. In addition, by using this electric blower, it is possible to realize a vacuum cleaner that is small and light, has a high suction work efficiency, and is easy to use.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Rotating shaft 3 Coil 4 Stator core 5 Frame 6 Bracket 7 Bearing 8 Bearing 9 Impeller 10 Air guide 11 Fan case 12 Resin ring 13 Outer cylinder 14 Ventilation path 15 Hole 16 Fin 17 Sound absorbing material 18 Groove 19 Ventilation Hole 20 Ventilation hole 21 Teeth 101 Rotor 102 Rotating shaft 103 Coil 104 Stator core 105 Frame 107 Bearing 108 Bearing 109 Impeller 110 Air guide 113 Outer cylinder 114 Ventilation path

Claims (7)

A brushless motor including a rotor having a rotating shaft, a stator having a core and a plurality of coils, and a frame holding a bearing that includes the stator and supports the rotating shaft. An impeller having a blade and fixed to a rotating shaft; an air guide disposed on an outer periphery of the impeller; the impeller and the air guide are included; an air inlet is disposed in a central portion; and at least the frame or the A fan case fixed to a part of the air guide, and an outer cylinder part including an outer cylinder connection part connected to the fan case and an outer cylinder provided outside the frame, and generated by the impeller, A passage through which the air guided to the air guide flows along the outer periphery of the frame is configured between the outer cylinder and the frame, and the core of the stator is disposed on the outer periphery of the frame. Electric blower provided a plurality of holes and less than the length of the rotation axis direction of the core with respect to the rotation axis direction to a position. The electric blower according to claim 1, wherein the shape of the hole on the outer periphery of the frame is a long hole in a direction along the flow of the swirling airflow from the air guide. The electric blower according to claim 1, wherein the holes on the outer periphery of the frame are arranged in a staggered manner. 2. The electric blower according to claim 1, wherein the electric blower is configured to have a fin formed by cutting and bending a hole on the outer periphery of the frame, and the fin is in a direction along a flow of a swirling airflow from the air guide. The stator core is provided with a groove on the outer peripheral surface of the core, which is an extension line in the radial direction of the teeth protruding toward the inner diameter side of the core, and the groove communicates with the end faces on both sides of the core in the rotation axis direction. The electric blower according to claim 1 configured as described above. The electric blower according to claim 5, wherein the hole on the outer periphery of the frame is aligned with the position of the groove on the outer periphery of the core. The vacuum cleaner carrying the electric blower of any one of Claims 1-6.