JPH08177859A - Bearing for fan - Google Patents

Abstract

PURPOSE: To form a proper oil film at all times by setting an oil absorptivity of pores in the area not made in contact with a rotating shaft larger than that in the area made in contact with the rotating shaft in a bearing surface. CONSTITUTION: An oil absorptivity is reduced in the area AR1 of a bearing surface 50 where is made in contact with a rotating shaft 6 so as to prevent the absorption of lubricating oil into a bearing 5, thus leaving oil film between the rotating shaft 6 and the bearing surface 50. Also, an oil absorptivity is increased in the area AR2 of the bearing surface 50 where is not made in contact with the rotating shaft 6 so as to increase the holding capacity of lubricating oil, thus increasing the amount of supply of lubricating oil from the inside of the bearing 5 when the rotating shaft 6 is rotated. By this, a proper oil film can be maintained at all times. Then the porosity of the bearing 5 is adjusted so that the oil absorptivity of pores in the area AR2 becomes larger by 20% or more than that in the area AR1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing used for supporting a rotary shaft of a blower fan of a vehicle air conditioner, for example.

[0002]

2. Description of the Related Art A rotary shaft of a blower fan driving motor (hereinafter referred to as a blower motor) provided in an intake unit of a vehicle air conditioner is conventionally rotatably supported by a slide bearing (for example, Japanese Unexamined Patent Publication No. Hei 2 (1999) -211). No. 223354, Japanese Utility Model Laid-Open No. 63-105467). Although there are various types of slide bearings, so-called sintered oil-impregnated bearings in which pores of a sintered alloy are impregnated with lubricating oil are used especially for the above-mentioned bearings for blower motors. The porosity of this sintered oil-impregnated bearing was constant over the entire circumference of the bearing surface.

[0003]

The slide bearing supports the load by the pressure of the oil film between the rotary shaft and the bearing surface, and
The lubrication action of the oil film reduces friction. Therefore, proper management of the oil film is indispensable to ensure the performance of the plain bearing. Here, the above-mentioned sintered oil-impregnated bearing has a property that when the rotating shaft stops, the lubricating oil is absorbed in the pores, and the lubricating oil is discharged from the pores when the rotating shaft is activated. The larger it is, the more it increases.
Therefore, if the porosity is excessively increased, a large amount of lubricating oil is absorbed from the bearing surface to the inside of the bearing when the rotating shaft is stopped, and the oil film may run out at the time of starting rotation. If the porosity is reduced, it becomes difficult for the lubricating oil to be absorbed into the bearing, and the oil film tends to remain even when the rotation is stopped. However, if the porosity is small, the bearing has a low lubricating oil holding capacity, and the amount of oil discharged from the inside of the bearing to the bearing surface after the rotation is started may be insufficient to form a sufficient oil film.

An object of the present invention is to provide a fan bearing which can always form an appropriate oil film.

[0005]

In a fan, such as a blower fan of an intake unit of a vehicle air conditioner, in which the blowing direction is limited to a fixed direction, the direction of the load acting on the rotating shaft is constant, so that the rotating shaft and the bearing are fixed. The surface always comes into contact with the surface through the oil film within a certain range, and the bearing surface and the rotary shaft do not come into contact with each other in other areas. The present invention focuses on this point and solves the above-mentioned problems by changing the state of the pores in both ranges of the bearing surface. That is, when it is described in association with FIG. 1 and FIG. 2 showing an embodiment, the invention of claim 1 creates pores capable of holding lubricating oil on the bearing surface 50 facing the rotating shaft 6 of the fan 2. Bearing 5 made of sintered material
And the oil absorption rate of the pores in the range AR2 of the bearing surface 50 which is not in contact with the rotary shaft 6 is in the range AR1 in which it is in contact with the rotary shaft 6.
Is set to be larger than the oil absorption rate of the pores to achieve the above-mentioned object. The oil absorption rate is a value obtained by comparing the amount of oil absorbed in the bearing 5 within a certain time with an appropriate reference value. The invention of claim 2 is applied to the fan bearing of claim 1, and the oil absorption rate of the pores in the range AR2 not in contact with the rotary shaft 6 is 20% or more with respect to the oil absorption rate in the range AR1 in contact with the rotary shaft 6. It is set large. Explaining with reference to FIG. 4A, the invention of claim 3 is applied to the fan bearing of claim 1, and the range A in which the bearing surface 50 is in contact with the rotating shaft 6 is described.
The first member 51 forming the R1 and the rotating shaft 6 of the bearing surface 50
The second member 52 forming the area AR2 that is not in contact with the second member 52 is connected. Further, with reference to FIG. 4B,
The invention of claim 4 is applied to the bearing for a fan of claim 1,
The bearing surface 50 is provided on the single member 53 over the entire circumference so that the range AR1 of the bearing surface 50 in contact with the rotary shaft 6 has a smaller oil absorption rate than the range AR2 of the rotary shaft 6 not in contact. It is sized. Referring to FIG. 5, the invention of claim 5 is applied to the fan bearing 5 of claim 4, and includes a positioning means 13b for positioning the bearing surface 50 in the circumferential direction during assembly.

[0006]

According to the first aspect of the invention, the oil absorption rate is reduced in the range AR1 of the bearing surface 50 in contact with the rotating shaft 6 to prevent the lubricating oil from being absorbed inside the bearing 5, and the rotating shaft 6 and the bearing surface 50 are Leave an oil film between them. In the range AR2 where the bearing surface 50 is not in contact with the rotating shaft 6, the oil absorption rate is increased to increase the lubricating oil holding capacity, and the amount of lubricating oil supplied from the inside of the bearing 5 when the rotating shaft 6 rotates is increased. As described above, an appropriate oil film can always be secured. In the invention of claim 2, the bearing surface 50
AR1 which is in contact with the rotation axis 6 and AR2 which is not in contact
With, the effect of changing the oil absorption rate can be surely produced. According to the invention of claim 3, the first oil absorption ratio is different.
The member 51 and the second member 52 can be manufactured separately. In the invention of claim 4, the oil absorption rate of the bearing surface 50 can be changed without increasing the number of parts of the bearing 5. According to the fifth aspect of the present invention, when the bearing 5 is assembled, the sized region can be correctly positioned within the range in contact with the rotary shaft 6.

Incidentally, in the section of means and action for solving the above problems for explaining the constitution of the present invention, the drawings of the embodiments are used for making the present invention easy to understand. It is not limited to.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a bearing of a rotary shaft of a blower fan of a vehicle air conditioner will be described with reference to FIGS. FIG. 2 shows a cross section of an intake unit of a vehicle air conditioner according to an embodiment, where 1 is a fan scroll, 2 is a blower fan, and 3 is a blower motor. The blower motor 3 has a substantially cylindrical casing 4 fixed to the fan scroll 1 by screws 4 a, bearings 5 arranged at both ends of the casing 4, and rotatably supported by the bearings 5, one end of which is connected to the blower fan 2. And a rotating shaft 6. The details of the bearing 5 will be described later.

Magnets 7 are arranged on the inner circumference of the casing 4 at appropriate intervals in the circumferential direction, and an armature 8 is provided on the rotary shaft 6 facing the magnet 7. When power is supplied to a coil (not shown) of the armature 8 from a power source (not shown) via the brush 9 and the commutator 10, the rotating shaft 6 rotates so as to cross the magnetic field of the magnet 7. As a result, air is taken in through the opening 1a of the fan scroll 1 as shown by the arrow in FIG.
The air is blown from (FIG. 3) to the subsequent air conditioning unit (not shown).

The bearing 5 is obtained by impregnating the pores of a sintered alloy with lubricating oil. A felt 11 impregnated with an appropriate amount of lubricating oil is arranged on the outer periphery of the bearing 5, and a bearing cover 12 is attached to the outside of the felt 11 to hold the bearing 5 and the felt 11 at predetermined positions. Here, FIG.
As described above, in this embodiment, since the blower fan 2 always blows air in a fixed direction from the blower fan 2 toward the connection port 1b of the fan scroll 1, the load (opposite to the blower direction acting on the blower fan 2) The direction of force P is also constant. Therefore, as shown in FIG. 1, the shaft center Cs of the rotary shaft 6 is always eccentric in the same direction with respect to the shaft center Cm of the bearing 5, and the rotary shaft 6 and the bearing surface 50 contact each other at a substantially constant contact point CP. . In addition,
The position of the contact point CP is displaced in the rotational direction (direction of arrow R) from the extension of the line of action of the load P acting on the shaft center Cs as the rotational speed of the rotary shaft 6 is higher. As described above, the position of the contact point CP changes variously depending on the rigidity of the bearing 5, the rotation speed of the rotary shaft 6, and the shape of the fan scroll 1. Therefore, it is desirable to confirm the actual contact point by an experiment or a simulation.

As described above, since the contact point CP between the bearing 5 and the rotary shaft 6 is substantially constant, the bearing surface 50 covers the rotary shaft 6 within the range AR1 of 90 ° to the left and right from the contact point CP in a total of 180 °.
The range AR2 on the opposite side to the range in contact with is assumed to be the range not in contact with the rotation axis 6. The oil absorption rate of the pores in the range AR2 is 20 than the oil absorption rate of the pores in the range AR1.
The porosity of the bearing 5 was adjusted so as to be larger than 0.1%. The ranges AR1 and AR2 do not necessarily have to be separated by 180 °. The reason why the difference in oil absorption rate is 20% or more is
This is because the improvement effect due to the change of the oil absorption rate is surely obtained. In some cases, even if it is less than 20%, improvement of the oil film can be expected as compared with the conventional example in which the oil absorption rate is constant over the entire circumference of the bearing surface 50. It should be noted that in FIG. 1, the pores are shown by small circles exaggerated from the actual size, and the actual pores are much smaller than those shown in the drawing.

According to the above structure, the absorption of the lubricating oil into the bearing 5 is suppressed in the area AR1 of the bearing surface 50 which is in contact with the rotating shaft 6, and the bearing 5 is in the area AR2 which is not in contact with the rotating shaft 6.
The discharge of the lubricating oil from the inside to the gap between the bearing surface 50 and the rotating shaft 6 is promoted. Therefore, the performance of the bearing 5 can be maintained high by always interposing an appropriate oil film between the bearing surface 50 and the rotary shaft 6.

Here, as a structure for changing the oil absorption rate described above, for example, the structure shown in FIG. 4 may be adopted.
FIG. 4A shows a range AR1 of the bearing surface 50 in contact with the rotating shaft 6.
And a semi-cylindrical second member 51 that constitutes a range AR2 that does not contact the rotation axis 6 of the bearing surface 50.
This is an example in which the member 52 is manufactured in separate steps, and then the two members 51 and 52 are abutted against each other to form the bearing 5. On the other hand, in FIG. 4B, a single sintered member 53 whose porosity is adapted to the range AR2 over the entire circumference is manufactured, and a portion X (FIG. 4) corresponding to the range AR1 on the inner peripheral surface of the member 53 is manufactured. Hatched area)
This is an example in which the oil absorption rate of the pores in the range AR1 is reduced by performing sizing processing on the.

In the example shown in FIG. 4B, the sizing portion X
If it cannot be confirmed at the time of assembly, the bearing 5 may be assembled in the circumferential direction in the wrong direction, and the sizing portion X may shift to the range AR2 where it does not contact the rotating shaft 6. Therefore, in the case of FIG. 4B, it is preferable to provide a means for positioning the bearing 5 in the circumferential direction. An example thereof is shown in FIG. FIG. 5A is a plan view of the bearing cover 12 of FIG. 2, and FIG. 5B is a bearing surface 5.
It is an enlarged view of the vicinity of 0. In this example, the convex portion 13a and the concave portion 1 are provided at one place of the facing surfaces of the bearing cover 12 and the bearing 5.
3b are respectively provided, and the bearing cover 12 and the motor casing 4 are provided at the positions where the convex portions 13a and the concave portions 13b are fitted to each other.
Are in close contact with each other, and the bearing 5 can be mounted in the correct direction in the circumferential direction. Note that the bearing 5 may be provided with only a mark indicating the mounting direction of the bearing 5 in the circumferential direction or an alignment index. As shown in FIG. 5, the bearing cover 12
When fixing the bearing cover 12 to the casing 4 with the screw 12a, the bearing cover 12 must be mounted in a constant circumferential direction.
The bearing 5 is not mounted in the correct orientation even if the concave portion 13b and the concave portion 3b are aligned. In such a case, for example, the casing 4
The protrusion 14a and the recess 14b of the bearing cover 12 prevent the bearing cover 12 from being erroneously mounted. The same applies to the mounting portion of the casing 4 and the fan scroll 1.

The present invention is not limited to bearings for blower motors, but can be applied to support the rotating shafts of various fans.

[0016]

As described above, in the present invention, the oil absorption rate in the range where the bearing surface is not in contact with the rotary shaft is made larger than that in the range where it is in contact with the rotary shaft, so that an appropriate oil film is always provided between the bearing surface and the rotary shaft. Can be formed to maintain high bearing performance. Particularly, in the invention of claim 2, the oil absorption rate in a range not in contact with the rotation axis is
Since it is larger than the range in contact with the rotating shaft by 20% or more,
The effect of changing the oil absorption rate can be surely exhibited. Further, in the invention of claim 3, the bearing can be manufactured by being divided into the first member and the second member having different oil absorption rates, so that the present invention can be easily implemented. According to the invention of claim 4, the oil absorption rate can be easily changed by the sizing process which is commonly used in the production of sintered materials, without increasing the number of bearing parts. According to the fifth aspect of the present invention, the sizing region of the single member can be properly positioned within the range in contact with the rotary shaft, and the desired performance of the bearing can be reliably exhibited.

[Brief description of drawings]

FIG. 1 is a sectional view of a bearing according to an embodiment of the present invention in a direction perpendicular to an axis.

FIG. 2 is a cross-sectional view of an intake unit of a vehicle air conditioner in which a bearing according to an embodiment of the present invention is used.

FIG. 3 is a plan view of the intake unit shown in FIG. 2 taken in the direction of arrow III.

FIG. 4 is a diagram illustrating a structure for changing an oil absorption rate of a bearing.

FIG. 5 is a view showing an example in which means for positioning the bearing in the circumferential direction is provided.

[Explanation of symbols]

 2 blower fan 3 blower motor 5 bearing 6 rotating shaft 11 felt 12 bearing cover 13a positioning protrusion 13b positioning recess 50 bearing surface 51 first member 52 second member AR1 range in contact with rotating shaft AR2 range not in contact with rotating shaft Cm Bearing shaft center Cs Rotating shaft shaft center CP Rotating shaft and bearing surface contact point

Claims (5)

[Claims] 1. A bearing surface facing a rotation axis of a fan,
In a fan bearing made of a sintered material, in which pores capable of holding lubricating oil are generated, in the bearing surface, the oil absorption rate of the pores in a range not in contact with the rotary shaft is in a range in contact with the rotary shaft. The fan bearing is set to be larger than the oil absorption rate of the pores. 2. The oil absorption rate of the pores in the range not in contact with the rotation axis is set to be 20% or more higher than the oil absorption rate in the range in contact with the rotation axis. Bearing for fan described. 3. A combined structure of a first member forming a range of the bearing surface in contact with the rotation axis and a second member forming a range of the bearing surface not in contact with the rotation axis. The bearing for a fan according to claim 1. 4. The bearing surface is provided on a single member over the entire circumference thereof, and the range of contact of the bearing surface with the rotary shaft has a smaller oil absorption rate than the range of non-contact of the rotary shaft. The fan bearing according to claim 1, wherein the bearing is sized as described above. 5. The fan bearing according to claim 4, further comprising positioning means for positioning the bearing surface in the circumferential direction during assembly.