JP2018194004A - Electric air blower and vacuum cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric blower and an electric vacuum cleaner capable of reducing vibration and noise. An electric blower 10 is configured to include a rotor having a shaft 31 rotatably provided and a rare earth-based bond magnet integrally molded with the shaft 31. The vacuum cleaner 1 includes an electric blower 10. [Selection diagram] Fig. 3

Description

  The present invention relates to an electric blower and a vacuum cleaner.

Generally, as an electric blower used for a vacuum cleaner, one using a DC brushless motor is known in order to reduce vibration and noise (see, for example, Patent Document 1).
In the rotor assembly which comprises the electric blower of patent document 1, the magnet is attached to the one end part of the shaft, and the impeller is attached to the other end part of the shaft. A bearing cartridge is attached to the shaft between the magnet and the impeller. The bearing cartridge includes a pair of bearings press-fitted into the shaft, a preload spring disposed between the bearings, and a case fitted on the pair of bearings.
Such a rotor assembly is assembled to the housing after assembly.

Special table 2012-518751 gazette

  In the electric blower of Patent Document 1, a magnet is attached to the shaft with an adhesive. As a result, a slight gap in which the adhesive is interposed is formed between the magnet and the shaft. For this reason, it is difficult to adjust the concentricity between the magnet and the shaft, and there is a problem that the concentricity is lowered to generate vibration and noise.

  This invention solves the said conventional problem, and it aims at providing the electric blower and vacuum cleaner which can aim at reduction of a vibration and a noise.

The electric blower of the present invention includes a rotor having a shaft provided rotatably and a rare earth-based bond magnet integrally formed with the shaft.
Moreover, the vacuum cleaner of this invention is provided with the said electric blower, It is characterized by the above-mentioned.

  According to the present invention, since the bond magnet is integrally formed on the shaft, the concentricity between the shaft and the bond magnet can be ensured with high accuracy.

  According to the present invention, an electric blower and a vacuum cleaner that can reduce vibration and noise can be obtained.

It is an external appearance perspective view which shows the external appearance of the vacuum cleaner to which the electric blower of this embodiment is applied. It is sectional drawing which showed the cleaner main body typically. It is sectional drawing of the electric blower of this embodiment. It is the perspective view which notched a part of electric blower and represented with the cross section. (A) is a side view of a rotor assembly, (b) is sectional drawing of a rotor assembly. (A) is explanatory drawing which shows the assembly | attachment of the rotor assembly to a housing, (b) is an expanded sectional view of the one end part of a bearing cover, (c) is explanatory drawing which similarly shows the mode after an assembly | attachment. (A)-(c) is explanatory drawing which shows the assembly procedure of a rotor assembly.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, in an electric blower, when saying "front and back", it is based on the direction shown in FIG.
As shown in FIG. 1, the vacuum cleaner 1 includes a vacuum cleaner body 2, a hose 3, an operation pipe 4 provided with a hand operation SW and the like, an extension pipe 5 as a joint pipe, and first and second pipes. The suction tools 6 and 7 are provided.
As shown in FIG. 2, an electric blower 10 that generates a suction force and a paper that is disposed in the dust collection chamber 2 c and collects the dust sucked in by the suction force of the electric blower 10, as shown in FIG. 2. A pack 8 (collecting member) and a filter 9 through which air from which dust has been removed by the paper pack 8 pass are disposed.

  The electric blower 10 is accommodated in the electric blower chamber 2a of the cleaner body 2 via the vibration isolating rubber 2b. As shown in FIG. 3, the electric blower 10 includes a housing 20, a rotor assembly (rotor) 30, and a stator assembly 40.

〔housing〕
As shown in FIG. 3, the housing 20 is made of synthetic resin and has a support portion 21 that supports the rotor assembly 30. The support portion 21 has a substantially cylindrical shape and is located inside the front portion of the housing 20. A cylindrical bearing cover 22 made of metal is fixed inside the support portion 21. The bearing cover 22 is integrally formed with the housing 20 (support portion 21). In the present embodiment, the housing 20 is formed by insert molding using the bearing cover 22 as an insert product. Bearings 36 and 37 included in the rotor assembly 30 are fitted into the inner surface of the bearing cover 22.

  A screw hole 21 a extending in the axial direction is formed in the front end portion of the support portion 21. A fixing screw 21b can be screwed into the screw hole 21a. A diffuser 25 (static blade) is fixedly installed at the front end portion of the support portion 21 by screwing a fixing screw 21b.

  An extended portion 23 extending in the radial direction is formed on the outer peripheral surface of the rear portion of the housing 20. The extending portion 23 supports the rear end portion of the outer case 26 that is mounted around the housing 20. A space in which the stator assembly 40 is disposed is formed in the inner space of the rear portion of the housing 20.

[Rotor assembly]
As shown in FIGS. 5A and 5B, the rotor assembly 30 includes a shaft 31, a rotor core 32, a bearing assembly 33, and an impeller 34. The rotor core 32, the bearing assembly 33, and the impeller 34 are attached to the shaft 31.

  The shaft 31 extends in the front-rear direction and is formed in a stepped columnar shape. The rotor core 32 is formed around a rear portion 31a, which is one end portion of the shaft 31, and is made of a rare earth-based bond magnet. A rare earth bond magnet is made by mixing a rare earth magnetic powder and an organic binder. As the rare-earth bond magnet, for example, a samarium iron nitrogen magnet or the like can be used.

The rotor core 32 is integrally formed with the shaft 31. In the present embodiment, the rotor core 32 is formed by insert molding. That is, the rotor core 32 is integrally formed with the shaft 31 without having a gap due to the presence of an adhesive as in the prior art. The samarium iron nitrogen magnet has a stronger magnetic force than a normal (sintered) ferrite magnet and is easy to process. Therefore, the electric motor of the vacuum cleaner 1 that is required to be small and rotate at high speed. It is suitable as the blower 10.
The outer peripheral surface of the rear portion 31a of the shaft 31 is knurled. The rotor core 32 can be strongly coupled to the shaft 31 by knurling.

  The bearing assembly 33 is a member for fixing the rotor assembly 30 to the housing 20, and is disposed between the rotor core 32 and the impeller 34. The bearing assembly 33 includes a pair of bearings 36 and 37, a spacer 38, and a spring 39.

  The pair of bearings 36 and 37 are the same. The spacer 38 has a cylindrical shape and serves to separate the pair of bearings 36 and 37 by a predetermined distance. The spring 39 is a coil spring that surrounds the spacer 38, is disposed in a compressed state, and abuts against the outer rings of the bearings 36 and 37 to apply preload.

The impeller 34 is made of a synthetic resin and is directly connected to the front portion on the other end side of the shaft 31. The impeller 34 is a centrifugal impeller that uses centrifugal force. When the impeller 34 rotates at a high speed, the pressure rises in the impeller 34, and air is sucked from a suction portion 26 c formed in the lid portion 26 b of the outer case 26. The sucked air is discharged as a high-speed air flow to the outer peripheral side through the impeller 34 (see FIGS. 3 and 4). The air flow discharged from the impeller 34 is guided to the diffuser 25. The diffuser 25 forms a diffuser flow path that guides the air flow discharged from the impeller 34 in the outer circumferential direction. As shown in FIG. 4, the air flow that has passed through the diffuser flow path is guided to the space S <b> 1 between the housing 20 and the outer case 26 (body portion 26 a), and is led out of the electric blower 10 through the outlet port 23 a. The outlet 23 a is formed in the extending part 23 of the housing 20.
The air flow guided to the space S1 flows into the housing 20 through the slit S2 of the housing 20, and is electrically driven between the rotor core 32 and the stator assembly 40 or between the conductors (not shown) of the stator assembly 40. It is led out of the blower 10. Thereby, each part in the housing 20 is cooled.

  A metal support sleeve 34 a formed by sintering or the like is attached to the center of the impeller 34. The support sleeve 34a has an inner peripheral surface into which the shaft 31 is press-fitted. Such a support sleeve 34 a is insert-molded on the impeller 34. The impeller 34 is fixed to the front portion of the shaft 31 by press-fitting the shaft 31 into the support sleeve 34a.

[Stator assembly]
As shown in FIG. 3, the stator assembly 40 is disposed in the rear inner space of the housing 20. The stator assembly 40 includes a stator core 41 disposed on the opposite side of the rotor core 32. A conductor (not shown) is wound around the stator core 41 to form a phase winding together. The phase winding is electrically connected to a circuit unit (not shown) provided in the electric blower 10.

  In the electric blower 10 as described above, as shown in FIG. 6, the outer diameter of the impeller 34 (the outer diameter of the bottom 34c) is Di, the outer diameters of the bearings 36 and 37 are Db, and the minimum inner diameter of the bearing cover 22 is When Dc is set and the outer diameter of the rotor core 32 is set to Dm, these relationships are set to satisfy Di> Db> Dc> Dm.

  Thus, the outer diameter Db of the bearings 36 and 37 is smaller than the outer diameter Di of the impeller 34, and the minimum inner diameter Dc of the bearing cover 22 is smaller than the outer diameter Db (the inner diameter of the opening edge 22b of the one end opening 22a, FIG. Since the outer diameter Dm of the rotor core 32 is smaller than the minimum inner diameter Dc, the rotor core 32 inserted into the bearing cover 22 has a minimum inner diameter Dc of the one end opening 22a (see FIG. 3). It passes through the portion and is inserted inside the stator assembly 40. At the same time, the bearing assembly 33 is inserted into the bearing cover 22, and the rear bearing 36 abuts the opening edge 22b of the bearing cover 22 from the inside (front side) and is positioned at the opening edge 22b (FIG. 6). (See (c)).

Next, manufacture and assembly of the rotor assembly 30 will be described.
First, as shown in FIG. 7A, the rotor core 32 is integrally formed on the rear portion 31a of the shaft 31 by insert molding. At this time, insert molding while applying a magnetic field gives the rotor core 32 a gradient for magnetization. In addition, the impeller 34 is molded by insert molding using the support sleeve 34a as an insert product.

  Thereafter, as shown in FIG. 7B, the bearing assembly 33 is attached to the central outer peripheral surface 31 c of the shaft 31. In this case, after the rear bearing 36 is press-fitted and fixed to the shaft 31 and the spacer 38 and the spring 39 are assembled, the front bearing 37 is press-fitted and fixed. The rear bearing 36 is positioned at a predetermined position by the protruding portion 31 b of the shaft 31.

Thereafter, as shown in FIG. 7C, the front portion of the shaft 31 is press-fitted into the support sleeve 34a of the impeller 34 with the spacer 35 interposed therebetween, and the impeller 34 is fixed to the shaft 31 with a tightening swivel. The impeller 34 is positioned at the front portion of the shaft 31 with the inner surface of the support portion 34 b in contact with the inclined portion 31 e and the small diameter portion 31 d at the front portion of the shaft 31.
Thus, the rotor assembly 30 is assembled.

  As shown in FIG. 5B, the support sleeve 34 a is disposed at a position close to the bottom 34 c of the impeller 34 and is fixed to the shaft 31. As a result, blurring that may occur around the intersection Y1 between the bottom 34c and the center of the shaft 31 (shake of the impeller 34 in the direction of the arrow X1 in the figure) is suitably suppressed.

Next, the rotational balance of the rotor assembly 30 is adjusted. For adjustment, a dedicated jig is used, and the rotor assembly 30 is actually rotated at high speed to check the balance. For example, the balance is adjusted by cutting an unbalanced portion. Further, since the magnetization has not yet been performed at this time, the rotor core 32 can be shaved and balanced.
When the balance has been adjusted, magnetization is performed to give the rotor core 32 a magnetic force. When the magnetization is finished, the rotor assembly 30 is assembled in the housing 20. That is, since the rotor assembly 30 is assembled into the housing 20 after the balance is adjusted, the electric blower 10 can be assembled while maintaining a good balance.
As shown in FIG. 6A, the diffuser 25 is fixed in advance in the housing 20, and the rotor assembly 30 is inserted into the housing 20 through the diffuser 25.

As described above, the rotor assembly 30 and the bearing cover 22 are such that the outer diameter Db of the bearings 36 and 37 is smaller than the outer diameter Di of the impeller 34, and the minimum inner diameter Dc of the bearing cover 22 is smaller than the outer diameter Db. Further, since the outer diameter Dm of the rotor core 32 is smaller than the minimum inner diameter Dc, the rotor assembly 30 can be smoothly assembled to the housing 20 (bearing cover 22) (see FIG. 6C).
The bearings 36 and 37 can be fixed to the bearing cover 22 with an adhesive.

  According to the electric blower 10 of the present embodiment described above, the rotor core 32 is formed on the shaft 31 by insert molding (integral molding). Therefore, there is no need to provide a gap for an adhesive as in the prior art, and the shaft 31 And the concentricity of the rotor core 32 can be increased. Therefore, the electric blower 10 that can reduce vibration and noise is obtained.

  Moreover, since the rotor core 32 can be strongly coupled to the shaft 31 by knurling applied to the surface of the rear portion 31a of the shaft 31, the idling of the rotor core 32 can be prevented.

Further, since the impeller 34 is press-fitted and fixed by the support sleeve 34a and is fixed to the shaft 31 with a tightening swivel, there is no need to provide a gap for the adhesive as in the prior art, and the shaft 31 and the impeller 34 are identical. The core can be increased. Therefore, the electric blower 10 that can reduce vibration and noise is obtained.
Thus, since the rotor assembly 30 having excellent concentricity is configured by insert molding and press-fitting without using an adhesive, the electric blower 10 with reduced vibration and noise can be obtained.

  Since the rotor assembly 30 is incorporated into the housing 20 after the overall balance is adjusted, the electric blower 10 capable of suitably reducing vibration and noise is obtained.

  Further, the rotor assembly 30 and the bearing cover 22 are such that the outer diameter Db of the bearings 36 and 37 is smaller than the outer diameter Di of the impeller 34, the minimum inner diameter Dc of the bearing cover 22 is smaller than the outer diameter Db, and the minimum inner diameter. Since the outer diameter Dm of the rotor core 32 is smaller than Dc, the assembly of the rotor assembly 30 to the housing 20 is smooth, and the assembly is excellent. Moreover, since it is excellent in assembly | attachment property, the balance of the rotor assembly 30 adjusted before the assembly | attachment can be maintained suitably after an assembly | attachment.

  In the embodiment, the rotor core 32 is provided at the rear portion 31a of the shaft 31, but the present invention is not limited to this, and the shaft 31 may be integrally formed at another position of the shaft 31.

  The shape of the housing 20 can be any shape as long as it can support the rotor assembly 30.

DESCRIPTION OF SYMBOLS 1 Electric vacuum cleaner 10 Electric blower 20 Housing 22 Bearing cover 30 Rotor assembly (rotor)
31 Shaft 32 Rotor core (bonded magnet)
33 Bearing assembly 34 Impeller 36 Bearing 37 Bearing 40 Stator assembly 41 Stator core Di Outer diameter of impeller Db Outer diameter of bearing Dc Minimum inner diameter of bearing cover Dm Outer diameter of rotor core

Claims (2)

  An electric blower comprising a rotor having a shaft provided rotatably and a rare earth-based bond magnet formed integrally with the shaft.   An electric vacuum cleaner comprising the electric blower according to claim 1.

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