JPH07190077A - Supporting member for rotating body - Google Patents

Abstract

PURPOSE:To enhance the pulling pressure and rotation preventing effect without excessively enlarging a press-in margin when the housing of a bearing is pressed and fixed into a case and fixed, and also facilitate the manufacture of the housing. CONSTITUTION:In a housing 11, a dropping-out preventing recessed groove 12 is formed on the outer circumferential surface of a press-in part 11a to be pressed into a case. The dropping-out preventing recessed groove 12 has one-directional inclined part 12a and reversed directional inclined part 12b inclined in mutually opposite directions to the circumference of the outer circumferential surface. The whole dropping-out preventing recessed groove 12 has a form drawn with a single stroke. Thus, the rotation not only in the axial direction but alto in both positive and reverse directions can be surely prevented by both the inclined parts 12a, 12b. The dropping-out preventing recessed groove 12 having the form drawn with one stroke can be easily machined by the machining by use of a lathe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supporting member for a rotating body such as an output shaft of a motor, for example, a metal bearing made of a sintered oil-impregnated bearing or a housing for supporting the metal bearing.

[0002]

2. Description of the Related Art FIG. 6 shows an example of an instrument using a motor 1. In the figure, 2 is a rotation output shaft of the motor 1. Reference numeral 6 is a case made of resin as a component to be attached, and a circular attachment hole 7 is formed in the case 6. Reference numeral 8 denotes a housing made of brass or the like, and the housing 8 is coaxially press-fitted and fixed in the mounting hole 7 of the case 6. A substantially cylindrical metal bearing 9 made of a sintered oil-impregnated bearing is coaxially press-fitted and fixed in the housing 8. The bearing 9 coaxially rotatably supports the output shaft 2 of the motor 1.

The housing 8 is, as shown in FIG.
The inner peripheral surface and the outer peripheral surface are parallel cylindrical surfaces, but the outer peripheral surface has a large-diameter portion 8a on one side in the axial direction and a press-fitting portion 8b having a smaller diameter on the other side in the axial direction. Between the large-diameter portion 8a and the press-fitting portion 8b, there is a step surface 8c located on a plane orthogonal to the axial direction. Then, as shown in FIG.
The press-fitting portion 8b is press-fitted into the mounting hole 7 of the case 6 from the direction shown by the arrow A, and the step surface 8c abuts the mounting hole 7 of the case 6 in the axial direction. Therefore, the direction indicated by the arrow B, which is opposite to the A direction, is the extraction direction.

Further, in the conventional housing 8, the outer peripheral surface of the press-fitting portion 8b is a smooth cylindrical surface without irregularities. However, in such a press-fitting portion 8b, when an external force is applied, the housing 8 easily moves axially or circumferentially with respect to the case 6, and the housing 8 with respect to the case 6 is easily moved.
It is uncertain how to prevent it from coming off. That is, the extraction pressure of the housing 8 is small.

One means for increasing the extraction pressure of the housing 8 is to increase the press-fitting margin, that is, (the outer diameter of the press-fitting portion 8b of the housing 8)-(the inner diameter of the mounting hole 7 of the case 6). However, if the press-fitting margin is too large, the inner diameter of the mounting hole 7 of the case 6 contracts, and the dimensional accuracy deteriorates.

Further, conventionally, as shown in FIG. 8, in general, an axial knurling 10 is formed on the outer peripheral surface of the press-fitting portion 8b to prevent it from coming off. However, the axial knurling 10 has a whirl-stop effect, but the axial slip-off prevention effect is weak.

On the other hand, it is conceivable to form an annular concave-convex portion along the circumference of the outer peripheral surface of the press-fitting portion 8b. Even if the effect is increased to some extent, the anti-rotation effect is weak. In particular, since the output shaft 2 of the motor 1 rotates, a force is easily applied to the housing 8 in the circumferential direction,
We must be able to withstand this.

[0008]

As described above, in the conventional housing, since the press-fitting portion into the case has a smooth cylindrical surface with no unevenness, the pull-out pressure is small, and the housing cannot be securely prevented from coming off from the case. There was a problem.
On the other hand, if an attempt is made to simply increase the press-fitting margin, there is a problem that the dimensional accuracy is deteriorated. Further, even if an axial knurl is formed on the outer peripheral surface of the press-fitting portion to prevent slipping off, the effect of preventing rotation is obtained, but the axial slip-off preventing effect is weak. On the other hand, even if the concavo-convex portion is formed along the circumference of the outer peripheral surface of the press-fitting portion, the effect of preventing rotation is particularly small.

The present invention is intended to solve such a problem, and in a supporting member for a rotating body such as a housing which is press-fitted and fixed to a mounted component such as a case, the press-fitting margin is excessively large. Without doing so, it is intended to increase the extraction pressure, and further to sufficiently enhance not only the axial direction but also the anti-rotation effect. Another object of the present invention is to facilitate the production of such a supporting member for a rotating body.

[0010]

In order to achieve the object of the former, the invention of claim 1 directly or indirectly supports the rotating body on the inner peripheral side, and the outer peripheral surface forming a cylindrical surface is covered. In a supporting member for a rotating body that is press-fitted and fixed in an attachment part, a one-way inclined part and a reverse-direction inclined part that are inclined in opposite directions with respect to a circumference of an outer peripheral surface of the attached part that is press-fitted. The retaining groove is formed.

According to a second aspect of the present invention, in the component for supporting a rotating body according to the first aspect of the invention, in order to achieve the latter object as well, a dropout formed in an outer peripheral surface press-fitted into the attached component. The entire stop groove is in a single stroke.

[0012]

According to the first aspect of the invention, the outer peripheral surface of the supporting member for a rotating body is press-fitted and fixed to the component to be mounted, and the rotating body is directly or indirectly supported on the inner peripheral side. Although the outer peripheral surface of the supporting member of the rotating body has a cylindrical surface, there is a retaining groove, and this retaining groove enhances the removal pressure for the mounted component. The retaining groove has a unidirectional slanted portion and a reverse slanted portion that are slanted in mutually opposite directions with respect to the circumference of the cylindrical surface, and supports the rotating body supporting component in the axial direction with respect to the mounted component. Not only to prevent it from coming off, but also to prevent it from turning in either forward or reverse directions.

According to the second aspect of the present invention, the retaining groove is formed in a single stroke, for example, in a lathe,
By appropriately feeding the cutting tool in the axial direction while rotating the supporting member of the rotating body, the retaining groove is formed at one time.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The supporting member of the rotating body of this embodiment is the metal bearing 9 as shown in FIG. 6 described above.
A housing 11 for supporting the. This housing 11
It is made of brass, and the inner peripheral surface of which the bearing 9 is coaxially press-fitted and fixed is a cylindrical surface. The outer peripheral surface of the housing 11 has a large-diameter portion 11a on one side in the axial direction and a press-fitting portion 11b having a smaller diameter on the other side in the axial direction. In between, there is a step surface 11c located on a plane orthogonal to the axial direction. Large part 11
Both a and the press-fitting portion 11b are cylindrical surfaces parallel to the inner peripheral surface. The press-fitting portion 11b is press-fitted and fixed in a circular mounting hole 7 of a case 6 made of resin as a component to be mounted, and the step surface 11c abuts the mounting hole 7 of the case 6 from the axial direction. is there. The outer diameter of the press-fitting portion 11b is about 7 mm.

A retaining groove 12 is formed on the outer peripheral surface of the press-fitting portion 11b. This retaining groove 12
Has a unidirectional sloping portion 12a and a reverse directional sloping portion 12b which are inclined in opposite directions with respect to the circumference of the housing 11.
In FIG. 3, the axial dimension is twice the radial dimension,
The cross-sectional shape of the retaining groove 12 is shown. The retaining groove 12 has a depth a of less than about 0.2 mm and a width b of about 0.1 mm. Further, as shown in FIG. 2, the retaining groove 12 has a one-stroke shape as a whole. FIG. 2 is a development view of the press-fitting portion 11b, in which the c lines at the left and right ends are the same bus bars of the press-fitting portion 11b. Also, the same display c1, c2, c on both c lines
3 and c4 indicate that they are at the same point. For example point c1
Trace from left to right in the figure starting from point c1 to point p1,
The point c2, the point p2, the point c3, the point p3, the point c4, and the point p4 are sequentially passed in this order to return to the point c1. The retaining groove 12 is a press-fitting part.
Neither the tip edge of 11b (upper side of FIG. 2) nor the stepped surface 11c (lower side of FIG. 2) is in contact.

Next, the operation of the above configuration will be described. The metal bearing 9 is fixed to the inside of the housing 11, and the press-fitting portion 11b is press-fitted and fixed to the mounting hole 7 of the case 6. The metal bearing 9 supports the output shaft 2, which is the rotating body of the motor 1, on the inner peripheral side. And press fitting part
The retaining groove 12 at 11b enhances the retaining effect on the case 6. Here, the test results for the withdrawal pressure are shown in Table 1 including the control example.

[0017]

[Table 1]

Here, the outer peripheral knurled product is the housing 8 having the knurling 10 in the press-fitting portion 8b as shown in FIG. 8 described above. Further, the non-peripheral groove product is the housing 8 in which the press-fitting portion 8b has a smooth cylindrical surface without unevenness as shown in FIG. Further, the product with the outer peripheral groove is the housing 11 of the present embodiment. Further, the product with the outer peripheral groove is a housing 11 of the present invention similar to that of the present embodiment, in which the outer diameter of the press-fitting portion 11b is further increased. The outer diameter of the housing is the press-fitting portion.
The outer diameter of 8b, 11b, and the press-fitting margin is the housing 8, 11
Is the difference between the outer diameter of the press-fitted portions 8b and 11b and the inner diameter of the mounting hole 7 of the case 6, and the withdrawal pressure is the force required when the housings 8 and 11 are removed from the case 6 in the B direction. And the numbers shown in Table 1 are the average of 5 samples for each of. As is apparent from the table, even if the press-fitting margin is the same, the housing 11 of the present embodiment
Also has a significantly higher extraction pressure than the housing 8 of the comparative example.

As described above, according to the structure of this embodiment, the retaining groove 12 can increase the extraction pressure without excessively increasing the press-fitting margin. That is, the fixing strength of the housing 11 to the case 6 can be increased. Since the press-fitting margin does not have to be excessively large, it is possible to prevent the inner diameter of the mounting hole 7 of the case 6 from contracting and the dimensional accuracy from deteriorating.

Moreover, the retaining groove 12 has a unidirectional inclined portion 12a which is inclined in opposite directions with respect to the circumference of the press-fitting portion 11b.
And the reverse slope 12b, the housing
Not only can the 11 be reliably prevented from slipping off from the case 6 in the axial direction, but it can also be reliably prevented from rotating in either the forward or reverse directions. The housing 11 supports the rotation output shaft 2 of the motor 1 via the bearing 9, and since a force is easily applied in the circumferential direction, it is possible to prevent rattling with continued use. In order to do so, the effect of the detent is important.

In manufacturing the housing 11, the outer peripheral surface is machined by turning using a lathe, for example.
At this time, the retaining groove 12 may be processed at the same time. Moreover, since the retaining groove 12 is formed in a single stroke, the retaining groove 12 can be formed at a time by properly feeding the cutting tool in the axial direction of the housing 11 while rotating the housing 11. . Therefore, the retaining groove 12 can be formed easily and quickly, and the processing time can be shortened.

The present invention is not limited to the above embodiment, and various modifications can be made. For example,
The shape of the retaining groove is not limited to that of the above-described embodiment, and as shown in FIG. 4, the retaining groove 16 may be entirely discontinuous. The retaining groove 16 has a plurality of pairs of unidirectional sloping portions 16a and reverse sloping portions 16b that are inclined in opposite directions with respect to the circumference of the press-fitting portion 11b. In addition, the retaining groove may be formed in various forms such as a wavy shape in which one-direction inclined portions and reverse-direction inclined portions are alternately arranged continuously or discontinuously.

Further, although the housing 11 of the bearing 9 is targeted in the above embodiment, the present invention can be applied to the bearing 21 itself which directly supports the rotating body as shown in FIG. 5, for example. FIG. 5 shows a metal bearing 21 composed of a sintered oil-impregnated bearing, which has a substantially cylindrical shape and slidably supports a rotating body such as a rotation output shaft of a motor on the inner peripheral side. . Further, a retaining groove 22 similar to that of the embodiment shown in FIGS. 1 to 3 described above is formed on the outer peripheral surface of the bearing 21 which is press-fitted and fixed in a housing or the like as an attached component. . The retaining groove 22 is formed in the bearing 21.
Has a unidirectional slanted portion 22a and a reverse slanted portion 22b which are slanted in opposite directions with respect to the circumference of the outer peripheral surface.

[0024]

According to the first aspect of the present invention, in the supporting member for the rotating body, the outer peripheral surface of the cylindrical surface which is press-fitted and fixed to the mounted component is provided in the directions opposite to each other with respect to the circumference. Since the retaining groove having the sloping one-way sloping portion and the sloping one-way sloping portion is formed, the removal pressure can be increased without excessively increasing the press-fitting allowance between the supporting member of the rotating body and the mounted component. In addition to being able to obtain a sufficient axial retaining effect, the supporting parts of the rotating body directly or indirectly support the rotating body on the inner peripheral side, whereas in both the forward and reverse directions. Sufficient anti-rotation effect can be obtained.

According to the second aspect of the present invention, the retaining groove is formed in a single stroke, so that the retaining groove can be easily and quickly formed during manufacturing, for example, by turning.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a supporting member for a rotating body of the present invention.

FIG. 2 is a development view of an outer peripheral surface of the press-fitting portion of the above.

FIG. 3 is a cross-sectional view of a part of the same press-fitting section.

FIG. 4 is a perspective view showing another embodiment of the rotating body supporting component of the present invention.

FIG. 5 is a perspective view showing still another embodiment of the supporting member of the rotating body of the present invention.

FIG. 6 is a cross-sectional view of an instrument using a rotating body supporting component.

FIG. 7 is a perspective view showing an example of a conventional supporting member for a rotating body.

FIG. 8 is a perspective view showing another example of a conventional supporting member for a rotating body.

[Explanation of symbols]

 2 Motor output shaft (rotating body) 6 Case (attached parts) 11 Housing (rotating body supporting part) 11b Press-fitting part (outer peripheral surface) 12 Detachment prevention groove 12a One-way inclined part 12b Reverse-direction inclined part 16 Missing Stop groove 16a One-way inclined section 16b Reverse-direction inclined section 21 Metal bearing (supporting part for rotating body) 22 Fall-out prevention groove 22a One-way inclined section 22b Reverse-direction inclined section

Claims (2)

[Claims] 1. A component for supporting a rotating body, which directly or indirectly supports a rotating body on an inner peripheral side and whose outer peripheral surface forming a cylindrical surface is press-fitted and fixed to a mounted component,
On the outer peripheral surface press-fitted to the attached component, there is formed a retaining groove having a unidirectional slanted portion and a reverse slanted portion which are slanted in opposite directions with respect to the circumference thereof. Supporting parts. 2. The component for supporting a rotating body according to claim 1, wherein the retaining groove formed on the outer peripheral surface to be press-fitted into the mounted component has a single stroke shape.