JP2007100622A - Air blowing fan and air blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air blowing fan capable of preventing a crack by a difference in a thermal expansion coefficient of an impeller being a mold, and capable of preventing deformation of a rotor yoke by insert molding. <P>SOLUTION: The rotor yoke 1 and a rotor shaft 4 are inserted into a metal mold for molding the impeller, integrally molded, and joined so that the peripheral resin thickness of an impeller embedding part 19 of the rotor yoke 1 becomes equal on the inner-outer peripheral side in the axial direction and the height of resin becomes equal on the inner-outer peripheral side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a blower fan and a blower.

  As an example of a blower, a blower using an outer rotor type motor will be described. In FIG. 4, the rotor yoke 53 and the impeller 54 are integrally formed, and the hub 52 and the rotor yoke 53 into which the rotor shaft 51 is fitted are caulked and assembled together. A cylindrical magnet (not shown) is fitted into the inner wall of the rotor yoke 53. The rotor shaft 51 is rotatably supported by a bearing housing (not shown) via a bearing. A stator and a motor board (not shown) are integrally assembled with the bearing housing.

  In the above-described blower, since the difference in coefficient of thermal expansion between the metal rotor yoke 53 and the resin impeller 54 is large, cracks may occur in the impeller 54 in a heat shock test or the like. In particular, if a weld line is formed when the impeller 54 is molded, it becomes a cause of cracks. Further, there is a problem that the rotor yoke 53 is easily deformed due to variations in resin pressure during injection molding.

  The present invention has been made to solve these problems, and its purpose is to prevent cracking due to the difference in thermal expansion coefficient of the impeller that is a molded product and to prevent deformation of the rotor yoke that is insert-molded. The object is to provide a blower fan and a blower that can be used.

In order to achieve the above object, the present invention comprises the following arrangement.
In the blower fan in which the impeller is integrally assembled to the rotor yoke and the rotor shaft,
The rotor yoke and rotor shaft are inserted into the mold for impeller molding, and these are integrally molded. The resin thickness around the impeller buried portion of the rotor yoke is equal in the axial direction and on the inner and outer peripheral sides, and the resin height is on the inner and outer peripheral sides. It is characterized by being joined to be equal to each other.
Further, in the blower, the blower fan rotates around the rotor shaft by using the above-described blower fan and a driving source provided in a space surrounded by the rotor yoke and supporting a rotor shaft with a stator. It is driven.

  If the above-described blower fan and blower are used, the rotor yoke and the rotor shaft are inserted into the impeller molding die, and these are integrally molded. The resin thickness around the impeller buried portion of the rotor yoke is in the axial direction and the inner and outer peripheral sides. Since it is joined to be equal, stress concentration is unlikely to occur, and since the resin height of the impeller buried portion is joined to be equal on the inner and outer peripheral sides, the resin pressure during injection molding is increased on the inner and outer peripheral sides. Furthermore, by reducing the contact area with the molding resin in the impeller buried portion of the rotor yoke, it is difficult for the impeller to crack due to the difference in thermal expansion coefficient, and the rotor yoke is deformed by the resin pressure during molding. It becomes difficult.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a best mode of a centrifugal blower according to the invention will be described with reference to the accompanying drawings. In the blower fan according to the present invention, the impeller is integrally assembled to the rotor shaft of the rotor yoke, and the blower using the blower fan is suitably used as a cooling fan for a vehicle, for example.

A schematic configuration of the blower will be described with reference to FIG.
In FIG. 2, a stator 2 is provided in a space surrounded by the rotor yoke 1. The stator 2 is assembled to the bearing housing 3. The rotor shaft 4 is rotatably supported by the bearing housing 3 via a bearing 5. When the motor is energized, the blower fan 6 is driven to rotate about the rotor shaft 4. The motor may be either a motor with a brush or a brushless motor, but a brushless motor is desirable in order to reduce noise.

  In FIG. 1, a blower fan 6 is used in which a rotor yoke 1 and a rotor shaft 4 are inserted into a mold for impeller molding and these are joined by integral molding. Thus, since the rotor yoke 1 and the rotor shaft 4 are inserted into the impeller molding die and joined together by integral molding, the number of manufacturing steps is reduced and the productivity is improved. A high degree of coaxiality can be assembled, and the tendency of the deviation of the center of gravity becomes uniform, so that the rotation balance can be easily corrected.

  At the center of the impeller 7, the upper end side of the rotor shaft 4 is molded by being inserted into an impeller molding resin. A rotor yoke 1 is coaxially disposed around the rotor shaft 4 and is integrally formed. The rotor yoke 1 is integrally molded with the impeller buried portion 8 on the upper end side being inserted into the impeller molding resin. Bonding is performed so that the resin thickness around the impeller buried portion 8 is equal in the axial direction and the inner and outer peripheral sides. For example, in the axial direction, the resin thickness T1 = T2, and on the inner and outer peripheral sides, the outer peripheral side thickness T3 = T4 is equal to the inner peripheral side thickness T5 (resin thickness T3 = T4 = T5). Further, the entire resin thickness around the impeller buried portion 8 is molded such that the resin thickness T1 = T2 = T3 = T4 = T5. In this way, if the resin thickness around the impeller buried portion 8 of the rotor yoke is uniform, stress concentration is unlikely to occur, and the resin height of the impeller buried portion 8 is joined so as to be equal on the inner and outer peripheral sides (see FIG. 1), the resin pressure at the time of injection molding can be offset on the inner and outer peripheral sides, and by reducing the contact area with the molding resin at the impeller buried portion 8 of the rotor yoke 1, the rotor pressure is reduced by the resin pressure at the time of injection molding. The deformation of 1 is unlikely to occur, and the impeller 7 is not easily cracked due to the difference in thermal expansion coefficient.

  In FIG. 2, a knurled 9 is formed on the outer peripheral surface of the impeller buried portion 4 b on the upper end side of the rotor shaft 4. The knurling 9 increases the contact area in the circumferential direction of the impeller buried portion 4b to prevent rotation. Further, the strength against the tilt of the rotor shaft 4 is maintained by providing the cylindrical boss portion 10 in the axial direction of the impeller buried portion 4b.

  3 (a) and 3 (b), an upper end side corresponding to the impeller buried portion 8 of the rotor yoke 1 is formed with a bent portion 1a bent in an L shape, and is buried and joined in the impeller molding resin. The The bent portion 1a serves to prevent the rotor yoke 1 from coming off in the axial direction. Further, the bent portion 1a is formed with a notched portion 1b in which a part in the circumferential direction is notched. When the notch 1b is filled with resin and joined, the rotor yoke 1 integrally formed with the impeller 7 is prevented from rotating.

  In FIG. 2, the blower fan 6 is rotatably supported by inserting the rotor shaft 4 into a bearing 5. A thrust receiver 11 is provided below the bearing 5, and a pivot (R surface) 4 a formed at the lower end of the rotor shaft 4 is supported by the thrust receiver 11.

  A motor substrate 12 and a stator core 13 are assembled on the outer periphery of the bearing housing 3. A motor coil 14 is wound around the teeth portion of the stator core 13. A rotor magnet 15 is provided on the inner wall surface of the rotor yoke 1 so as to face the teeth portion. When the motor coil 14 is energized, the impeller 7 integrally formed with the rotor yoke 1 is rotated by repeatedly repelling and attracting the stator magnetic pole and the magnet magnetic pole.

It is sectional drawing of a ventilation fan. It is a half sectional view showing the composition of a blower. It is the top view and sectional drawing of a rotor yoke. It is a half section showing the composition of the conventional blower.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor yoke 1a Bending part 1b Notch part 2 Stator 3 Bearing housing 4 Rotor shaft 4a Pivot 4b, 8 Impeller buried part 5 Bearing 6 Blower fan 7 Impeller 9 Knurl 10 Boss part 11 Thrust receiver 12 Motor board 13 Stator core 14 Motor coil 15 Rotor magnet

Claims (2)

In the blower fan in which the impeller is integrally assembled to the rotor yoke and the rotor shaft,
The rotor yoke and rotor shaft are inserted into the mold for impeller molding, and these are integrally molded. The resin thickness around the impeller buried portion of the rotor yoke is equal in the axial direction and on the inner and outer peripheral sides, and the resin height is on the inner and outer peripheral sides. It is joined so that it may become equal in.   The blower fan is driven to rotate about the rotor shaft by using the blower fan according to claim 1 and a drive source in which a stator is provided in a housing that is provided in a space surrounded by the rotor yoke and supports the rotor shaft. A blower characterized by that.

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