CN104806540A

CN104806540A - Small-power ventilation fan directly driven by permanent magnet motor

Info

Publication number: CN104806540A
Application number: CN201510161918.9A
Authority: CN
Inventors: 叶露微
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-04-06
Filing date: 2015-04-06
Publication date: 2015-07-29

Abstract

The invention discloses a small-power ventilation fan directly driven by a permanent magnet motor. The small-power ventilation fan directly driven by the permanent magnet motor comprises an impeller which rotates according to a preset direction and the permanent magnet motor which directly drives the impeller, the impeller is axial flow type impeller or centrifugal type impeller, the impeller is molded by injection molding, and the diameter is less than or equal to 200 millimeters; a motor stator comprises 2 poles, 4 poles or 6 poles, the winding of the stator is connected with an alternating current power supply according to a specified winding direction; a motor rotor is a permanent magnetic rotor, and the pole number is the same with that of the stator; both the stator core and permanent magnetic rotor are cylindrical and located at two sides of a cylindrical air gap; the permanent magnetic rotor is divided into a front post, a middle post and a rear post in sequence along the axial direction, the residual magnetism of the middle post is higher than the residual magnetism of each of the front post and rear post, and the length of the stator core is larger than the length of the middle post and smaller than the length sum of the front post, middle post and rear post. The small-power ventilation fan directly driven by the permanent magnet motor enables the anti-inversion starting ability of the ventilation fan to be improved without greatly increasing the manufacturing cost.

Description

The direct drive low-power ventilating fan of a kind of permanent magnet motor

Technical field

The present invention relates to the direct drive low-power ventilating fan of a kind of permanent magnet motor, particularly relate to coordinating of its characteristic and electromagnetic structure, in International Patent Classification (IPC), classification can belong to F04D25/08.

Background technique

The applicant proposed a kind of with permanent magnet motor drive low-power ventilating fan, can obviously energy-conservation and reduce manufacture cost, see Chinese invention patent CN102330702B.But ventilation fan has the situation in face of the outdoor exhaust of reverse wind direction, also needs enough anti-reflective to turn startup ability.

Summary of the invention

Technical problem to be solved by this invention is, proposes the direct drive low-power ventilating fan of a kind of permanent magnet motor, when not too increasing manufacture cost, can improve its anti-reflective and turning startup ability.

The technological scheme that the present invention solve the technical problem is, the direct drive low-power ventilating fan of a kind of permanent magnet motor, comprising: the impeller rotated according to predetermined direction and the permanent magnet motor of this impeller of Direct driver, and:

A) impeller is axial flow or centrifugal, molding and forming, and diameter is not more than 200mm;

B) number of poles of motor stator is 2 poles or 4 poles or 6 poles, the winding of stator by regulation around to being access to ac power supply;

C) motor rotor is p-m rotor, and its number of poles is identical with the number of poles of stator;

It is characterized in that: iron core and the p-m rotor of described stator are Ring-cylindrical, and be positioned at air gap two side of Ring-cylindrical; For front pillar, center pillar and rear pillar that p-m rotor divides vertically successively, the remanent magnetism of center pillar is higher than the remanent magnetism of front pillar, rear pillar, and the length of stator iron core is greater than the length of center pillar and is less than front pillar, center pillar and rear column length sum.

The optimal design of this technological scheme is: described front pillar, center pillar and rear column length are respectively 0.35 ~ 0.65 times of armature core cylindrical length.

Higher and the performance of mixed cost is also higher and cost is lower and permanent-magnet material that performance is also lower dexterously in permanent magnet motor magnetic circuit for this technological scheme, is fully used in the end space of motor and magnetic field, thus improves the utilization factor K of permanent magnet motor _a, can when not too increasing manufacture cost, the anti-reflective improving ventilation fan turns startup ability.

Accompanying drawing explanation

Fig. 1 is the main Visual figure of the basic mechanical structure of embodiment of the present invention ventilation fan.

Fig. 2 is the permanent magnet synchronous motor electromagnetism basic structure schematic diagram of embodiment of the present invention ventilation fan;

Fig. 3 is A-A cross-sectional view in Fig. 2.

Embodiment

Embodiment of the present invention ventilation fan improves to form on the basis of embodiment 1 ventilation fan described in the authorized patent of invention CN102330702B of the applicant.

The basic mechanical structure of this ventilation fan (is equivalent to Figure of description 2 in CN102330702B) as shown in Figure 1.This is a family expenses small-power axial flow ventilation fan, mainly comprises:

---be fixed on the motor 2 of casing;

---be directly connected in the aial flow impeller 1 that this motor output shaft is rotated counterclockwise, it has 4 blades; By blast requirement, the number of blade also can be 3,5 or 6, but had better not more than 8, and odd number sheet as far as possible, to reduce vibration noise.Impeller is molding and forming, diameter 150mm.Impeller diameter is maximum does not exceed 200mm, and rotary inertia should be as far as possible little, to coordinate the starting torque that motor 2 is still not too large;

---motor 2 is internal rotor permanent-magnetic synchronous motor, its electromagnetism basic structure (is equivalent to Figure of description 2 in CN102330702B) as shown in Figure 2: the stator 100 and the cylindrical magnet rotor 200 that comprise Ring-cylindrical, and the two separates outer two sides in the inner by Ring-cylindrical air gap.Can find out as shown in Figure 2:

---rotor 200 is its cross sections with two orthogonal symmetry axis 400 is divided into 4 symmetrical 90 ° fan-shaped and each radial magnetizing 4 pole p-m rotors that are N, S, N, S;

---stator 100 is made up of the circular iron core 101 and winding 102 with 4 salient poles; Winding 102 is the coil parts 102 respectively around at 4 salient poles with Insulating frame, then by around being 4 poles to being connected in series, and thus produces the main flux passing through air gap between rotor of 4 poles when being energized;

---between each salient pole of stator iron core 101 and rotor 200 air gap width in the counterclockwise direction gradual change narrow; Therefore when free state and no electric circuit and without outer gas stream and rotational structure good, rotor 200 attracts by stator iron core, namely the permanent magnet flux axis 700,800 that namely geometrical axis of each pole passes through air gap between rotor passes through the main flux axis 500,600 of air gap between rotor for reference with the geometrical axis of adjacent stators salient pole respectively, deflects a less acute angle Ω in the counterclockwise direction.It is 5 ° (electrical angles 10 °) that the present embodiment designs this mechanical angle.The ratio that this angle can narrow with gradual change and changing, and affect detent torque and efficiency.When this design can avoid rotor in a free state stay in the dead in line of its axis and stator salient poles and make energising, detent torque is what is called " dead point " position of zero, and the rotor during the reluctance torque formed also helps and prevents from operating does not produce torque and stall when alternating current (a.c.) zero passage;

---linear Hall element 300, near the position of rotor 200 circumference on the axis 500 being installed on salient pole on the right side of stator iron core 100.

Can see the specification in CN102330702 and each accompanying drawing to the control of this motor.

Embodiment of the present invention ventilation fan to the improvement of ventilation fan described in CN102330702 mainly to the overall ferrite that motor 2 is former and stator core 101 is isometric or overall rubidium iron boron p-m rotor 200 Amending design as Fig. 3:

---the pole parts of p-m rotor 200 is made up of 3 sections of permanent magnetism hollow cylinders of axis, is followed successively by front pillar 201, center pillar 202 and rear pillar 203, and center pillar 202 is bonding rubidium iron boron, and front pillar 201 and rear pillar 203 are bonded ferrite.3 sections of permanent magnetism hollow cylinders penetrate rotating shaft 205 successively and put into mold injection, and be injection molding formed plastic stent 204 and be fixed on rotating shaft 205, then magnetizing is 4 poles;

---the length L22 of center pillar 202 is 0.35 ~ 0.65 times of stator core 101 length L1, its position in rotating shaft as far as possible after motor assembling relative to the middle part of stator core 101 length L1, namely its axially two ends with stator core 101 2 end apart from equal; Front pillar 201 and rear pillar 203 are preferably isometric; Magnetic pole overall length L after the assembling of front pillar 201, center pillar 202 and rear pillar 203 is 1.05 ~ 1.95 times of stator core 101 length L1.

Experiment shows, the motor of this design when the length L of stator 100 especially stator iron core 101 and external diameter constant, compare and the former motor of overall ferrite permanent-magnet rotor isometric with stator core, torque improves (31 ~ 96) %, compare and the former motor of overall rubidium iron boron p-m rotor isometric with stator core 101, torque improves about 15% but the cost of permanent-magnet material reduces.

Also can be designed for above-mentioned the ventilation fan the effect of the ventilation fan performance that is improved that use the ventilation fan of receded disk impeller and other permanent magnet motor (such as outer rotor permanent magnet motor or permanent magnet DC brushless motor) to drive similarly.

Claims

1. the direct drive low-power ventilating fan of permanent magnet motor, comprising: the impeller rotated according to predetermined direction and the permanent magnet motor of this impeller of Direct driver, and:

2. according to ventilation fan described in claim 1, it is characterized in that: the length of the front pillar of described p-m rotor, center pillar and rear pillar is respectively 0.35 ~ 0.65 times of the length of stator iron core.