JP2553251Y2 - Dynamic pressure bearing device for fan motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a hydrodynamic bearing device for a fan motor.

<Prior Art> Conventionally, a fan motor used for an office machine or the like is shown in FIG. This fan motor has blades 50,5
The shaft 53 has dynamic pressure generating parts 52, 52, and a fitting part 56 provided in a case 55 to which the stator 54 is fixed, the fitting part 56 being rotatably fitted with the shaft 53. The dynamic pressure bearing 57 is provided. , And the rotor 51 are supported in the radial direction via the dynamic pressure bearing 57, and the blades 50, 50,.
It was rotatably supported around. Then, the rotor 51 is rotated by the rotating magnetic field generated by the stator 54 to rotate the blades 50, 50,... To generate an airflow in the direction indicated by the arrow X in the drawing. The thrust load (see the arrow Y in the figure) acting on the shaft 53 as a reaction force of the thrust of the blades 50, 50 ... is a flange portion having a surface perpendicular to the axis provided at the end of the shaft 53. 58 and the above-mentioned fitting portion 56 opposed thereto
And a thrust dynamic pressure bearing 60 composed of the end face 59 of the bearing.

<Problems to be solved by the invention> However, the conventional fan motor bearings described above
The thrust load acting on the 53 as a reaction force of the thrust of the blades 50, 50 ... is supported by the thrust dynamic pressure bearing 60 which requires high machining accuracy for the right angle and the like, so the structure becomes complicated,
There was a problem that the cost could not be reduced. Further, a certain dimension is required in the axial direction in order to provide the thrust dynamic pressure bearing 60, and this has a problem that the compactness is hindered.

Further, when the shaft 53 is removed, the end face of the fitting portion 56 and the flange portion 58 are engaged with each other, so the snap ring 68 must be removed and the flange 58 must be removed. It was difficult, and there was a problem that this hindered the maintenance of the fan motor.

Therefore, the purpose of the present invention is to provide a thrust load acting as a reaction force of the thrust of the blade with a simple configuration without requiring a special mechanism such as a thrust dynamic pressure bearing, and to provide a fan motor dynamic which is easy to maintain. It is to provide a pressure bearing.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a rotating shaft having one end connected to a blade and a rotor via a supporting member, and a stator opposed to the rotor at an outer peripheral portion. A substantially cylindrical case in which a fitting portion into which the rotating shaft is fitted is disposed at a substantially central portion, and a dynamic pressure generating portion is provided on one of the rotating shaft and the fitting portion. A dynamic bearing device for a fan motor that rotatably supports the blades and the rotor around a stator, wherein the rotating shaft is removably fitted to the fitting portion and faces an end surface on the other end side of the rotating shaft. A resin receiving member provided in the case, wherein the stator is provided at a position shifted in the axial direction with respect to the rotor, and a shaft of an attractive force acting between an iron core of the stator and a magnet of the rotor. Direction component An axial component obtained by subtracting the thrust of the blade from the attraction acting between the stator and the rotor while attracting the rotor in the axial direction by a magnetic force that is greater than the thrust and opposite to the thrust in the axial direction. The remaining thrust load of
The end surface of the other end of the rotary shaft is supported by being brought into light contact with the receiving member.

<Operation> The rotating shaft is supported in the radial direction by the dynamic pressure generated by the dynamic pressure generating portion provided on one of the rotating shaft and the fitting portion along with the rotation. Accordingly, the blade and the rotor are rotatably supported around the stator via the dynamic pressure generating unit, are rotated by a rotating magnetic field generated by the stator, and are blown by the blade.

In addition, the axial component of the suction force between the rotor and the stator is balanced by the thrust of the blade and the receiving member at the shaft end, and the rotating shaft is moved in the axial direction by light contact between the shaft end surface and the receiving member. The shaft can be supported, the rotating shaft can be rotated with a small rotating torque, and the frictional resistance between the shaft end face and the receiving member can be reduced.

In addition, by adopting a configuration in which the rotating shaft (rotor) is removably fitted to the fitting portion (case), the assembling process of the fan motor can be simplified, the manufacturing becomes easy, and the cost can be reduced. In addition, the replacement and replenishment of the lubricant in the dynamic pressure generating portion can be easily performed, and the maintenance is facilitated.

In addition, by adopting a configuration in which a resin receiving member facing the end surface on the other end side of the rotating shaft is provided in the case, the axial movement of the rotating shaft can be regulated by this receiving member. Therefore, no noise is generated because the blades do not vibrate in the axial direction, so that noise generation can be prevented. Further, with this receiving member, the relative positional relationship between the groove for generating the dynamic pressure and the inner peripheral bearing surface of the fitting portion facing the groove can be prevented from shifting, so that the reduction in the bearing rigidity in the radial direction can be prevented. Thus, the rotating shaft can be reliably supported in the radial direction. Also,
Since the receiving member is made of resin, the manufacturing of the receiving member is easy, the frictional resistance between the receiving member and the rotating shaft can be reduced, and the rotating shaft can be smoothly rotated.

<Example> Hereinafter, the present invention will be described in detail with reference to an illustrated example.

In FIG. 1, 1 is an annular case extending in the radial direction,
Reference numeral 2 denotes a cylindrical fitting portion protruding from the center of the case 1, 3 denotes a stator provided on the outer periphery of the fitting portion 2, and 4 denotes a rotation while maintaining a constant gap in the fitting portion 2 in the radial direction. A rotating shaft which is freely and freely inserted and removed and has grooves 2a and 2a for generating dynamic pressure on its outer periphery, 5 is a resin receiving member for supporting the rotating shaft 4 provided in the case 1, and 6 is the fitting This is a dynamic pressure bearing composed of the part 2 and the rotating shaft 4. Reference numeral 7 denotes a cylindrical support member fixed coaxially to the shaft 4 and one end is closed. Reference numeral 8 denotes a rotor 9 fixed to the inner periphery of the support member 7 and the support member 7.
Are a plurality of blades protruding from the outer periphery of the support member 7 at regular intervals in the circumferential direction. The cylindrical space formed between the fitting portion 2 and the shaft 4 is filled with grease 11.

The fitting part 2 is a cylindrical part protruding from the center of the case 1.
12 is fitted inside.

The rotor 9 is rotatably supported around the stator 3 via a dynamic pressure bearing 6. The rotor 9 rotates in a direction indicated by an arrow a in the figure due to a rotating magnetic field generated by the stator 3, and blows in a direction indicated by an arrow b by blades 10, 10,... . During this rotation, the rotating shaft 4 is supported in the radial direction by the dynamic pressure generated in the grease 11 for generating the dynamic pressure in the grooves 2a for generating the dynamic pressure. Rotate in a state. On the other hand, the blades 10,10,
The thrust load (see the arrow c in the figure) acting on the rotating shaft 4 as a reaction force of the blowing action is an axial component of an attractive force acting between the iron core of the stator 3 and the magnet 8 of the rotor 9. Supported by. At this time, the attracting force acting between the stator 3 and the magnet 8 is generated by the blades 10 and 1.
As shown in FIG. 1, the blades 10, 10,... Are rotated at a high speed because the thrust loads generated by the thrusts of 0,. Even when the maximum thrust load is applied to the rotating shaft 4, the end face of the rotating shaft 4 only contacts the receiving member 5 made of resin lightly.

Thus, the dynamic pressure bearing 6 and the resin receiving member 5 provided in the case 1 constitute a fan motor bearing, and the rotating shaft 4
The thrust load (arrow c in the figure) acting as a reaction force of the air blowing of the blades 10, 10,... Is not supported by providing a special thrust dynamic pressure bearing as in the related art. The rotor 9 is opposed to the magnet 8 by an attractive force acting on the rotor 8, and the end face of the rotating shaft 4 is supported by the resin receiving member 5. Therefore, the dynamic pressure bearing device for the fan motor, and thus the fan motor, can be simplified. Configuration. Also,
It is possible to make the fan motor compact.

Further, the axial component of the suction force between the rotor 9 and the stator 3 is balanced by the thrust of the blade 10 and the receiving member 5 at the shaft end so that the end surface of the shaft 4 and the receiving member 5 can be lightly contacted. Thus, the rotating shaft 4 can be supported in the axial direction, the rotating shaft 4 can be rotated with a small rotating torque, and the frictional resistance between the end surface of the shaft 4 and the receiving member 5 can be reduced.

The shaft 4 connected to the blades 10, 10,...
Since the fan motor is detachably fitted to the bearing 6, the assembling process of the fan motor can be simplified, the production becomes easy, and the cost can be reduced. Also, grease 11 as a lubricant for the dynamic pressure bearing 6 can be easily replaced or replenished, and the dynamic pressure bearing for the fan motor, and consequently, the fan motor is very easy to disassemble and clean, so that maintenance is easy. Become.

Further, according to this embodiment, since the receiving member 5 made of resin facing the end face on the other end side of the rotating shaft 4 is provided in the case 1, the axial movement of the rotating shaft 4 is restricted by the receiving member 5. it can. Therefore, since the blade 10 does not vibrate in the axial direction and no abnormal noise is generated, noise generation can be prevented. Further, the receiving member 5 can prevent the relative positional relationship between the dynamic pressure generating groove 2a and the inner peripheral bearing surface of the fitting portion 2 facing the groove 2a from being shifted. The rotation shaft 4 can be reliably supported in the radial direction by preventing a decrease in rigidity.

Further, since the receiving member 5 is made of resin, the manufacturing of the receiving member 5 is easy, the frictional resistance between the receiving member 5 and the rotating shaft 4 can be reduced, and the rotating shaft 4 can be smoothly rotated.

In this embodiment, the groove for generating the dynamic pressure is provided on the shaft connected to the blade and the rotor. However, the groove may be provided on the inner periphery of a cylindrical fitting portion projecting from the center of the case. Further, it goes without saying that the dynamic pressure generating section is not limited to the dynamic pressure generating groove.

<Effects of the Invention> As is apparent from the above description, in the dynamic pressure bearing for a fan motor of the present invention, the rotating shaft is removably fitted to the fitting portion, and the resin is opposed to the other end surface of the rotating shaft. The stator is provided at a position shifted in the axial direction with respect to the rotor, and the axial component of the attraction force acting between the iron core of the stator and the magnet of the rotor is provided in the case. And the rotor is attracted in the axial direction by a magnetic force that is opposite to the thrust in the axial direction,
The remaining thrust load of the axial component obtained by subtracting the thrust of the blade from the suction force acting between the stator and the rotor is brought into light contact with the end face of the other end of the rotating shaft to the receiving member. I support it.

Therefore, according to the present invention, the axial component of the suction force between the rotor and the stator is balanced by the thrust of the blade and the receiving member at the shaft end, so that the shaft end surface and the receiving member are in light contact with each other. The rotating shaft can be supported in the axial direction, the rotating shaft can be rotated with a small rotating torque, and the frictional resistance between the shaft end surface and the receiving member can be reduced.

In addition, by adopting a configuration in which the rotating shaft (rotor) is removably fitted to the fitting portion (case), the assembling process of the fan motor can be simplified, the manufacturing becomes easy, and the cost can be reduced. In addition, the replacement and replenishment of the lubricant in the dynamic pressure generating portion can be easily performed, and the maintenance is facilitated.

In addition, by adopting a configuration in which a resin receiving member facing the end surface on the other end side of the rotating shaft is provided in the case, the axial movement of the rotating shaft can be regulated by this receiving member. Therefore, no noise is generated because the blades do not vibrate in the axial direction, so that noise generation can be prevented. Further, with this receiving member, the relative positional relationship between the groove for generating the dynamic pressure and the inner peripheral bearing surface of the fitting portion facing the groove can be prevented from shifting, so that the reduction in the bearing rigidity in the radial direction can be prevented. Thus, the rotating shaft can be reliably supported in the radial direction. Also,
Since the receiving member is made of resin, it is easy to manufacture the receiving member, and the frictional resistance between the receiving member and the rotating shaft can be reduced.
The rotating shaft can be smoothly rotated.

[Brief description of the drawings]

FIG. 1 is an axial cross-sectional view of a fan motor to which a fan motor dynamic pressure bearing according to one embodiment of the present invention is applied, and FIG. 2 is an axial direction of a fan motor to which a conventional fan motor dynamic pressure bearing is applied. It is sectional drawing. 1,55… Case, 2,56… Mating part, 2a, 52… Dynamic pressure generating part, 3,5
4… stator, 4,53… shaft, 5… resin receiving member, 6,57
... dynamic pressure bearings, 9,51 ... rotors, 10,50 ... blades.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-131736 (JP, A) JP-A-55-139051 (JP, A) Japanese Utility Model Showa 59-145257 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] A rotating shaft having one end connected to a blade and a rotor via a supporting member, a stator facing the rotor at an outer peripheral portion, and a fitting portion into which the rotating shaft is fitted at a substantially central portion. A dynamic pressure generating portion is provided on one of the rotating shaft and the fitting portion, and the fan rotatably supports the blade and the rotor around the stator. In the hydrodynamic bearing device for a motor, the rotating shaft is removably fitted to the fitting portion, and a resin receiving member facing the other end surface of the rotating shaft is provided in the case. The thrust is provided by being displaced in the axial direction with respect to the rotor, and the axial component of the attraction force acting between the iron core of the stator and the magnet of the rotor is larger than the thrust of the blade. For magnetic force in the opposite direction to the axial direction Along with suctioning the rotor in the axial direction, the remaining thrust load of the axial component obtained by subtracting the thrust of the blade from the suction force acting between the stator and the rotor is applied to the other end of the rotating shaft. A dynamic pressure bearing for a fan motor, wherein the end face is supported by making light contact with the receiving member.