JP3701731B2 - Transmission belt pulley - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission belt pulley, and more particularly to an improvement in a transmission belt pulley provided with a flange for preventing belt detachment at at least one side edge of a pulley outer peripheral portion for hanging the belt.
[0002]
[Prior art]
Conventionally, transmission belt pulleys used for belt transmission have been provided with flanges for preventing belt detachment on at least one side edge of the pulley outer periphery for hanging the belt. Such transmission belt pulleys are generally used. It is formed by casting, cutting and pressing.
For example, FIG. 7A is a partial cross-sectional view of a flat belt pulley 51 having a substantially cylindrical pulley outer peripheral portion 54 manufactured by processing such as cutting, and the outer periphery of the pulley fitted to the outer periphery of the bearing 2. The part 54 has flanges 53, 53 on both side edges, and constitutes a belt winding groove between the flanges 53, 53. The belt winding groove has a width slightly larger than the width of the belt to be hung, and the bottom of the groove is a flat belt winding peripheral surface 55 which is the outer peripheral surface of the pulley outer peripheral portion 54.
[0003]
FIG. 7B is a partial cross-sectional view of a flat belt pulley 61 provided with a substantially cylindrical pulley outer peripheral portion 64 manufactured by pressing, and the pulley outer peripheral portion 64 fitted to the outer periphery of the bearing 2. Has flanges 63, 63 on both side edges, and constitutes a belt winding groove between the flanges 63, 63. The belt winding groove has a width slightly larger than the width of the belt to be hung, and the bottom of the groove is a flat belt winding peripheral surface 65 which is the outer peripheral surface of the pulley outer peripheral portion 64.
[0004]
In such a pulley outer peripheral portion 54 (64), the corner portion where the inner side surfaces 56, 56 (66, 66) of both flanges 53, 53 (63, 63) intersect with the belt winding peripheral surface 55 (65). 57 (67) is provided with a rounded surface having an appropriate curvature so as to prevent stress concentration at the flange base portion. In particular, in the case of the pulley outer peripheral portion 64 formed by press working, a rounded surface is indispensable at the corner 67 of the flange base portion due to the restriction of the minimum bending radius at the time of press working.
[0005]
[Problems to be solved by the invention]
However, in the case of the pulley outer peripheral portion 54 (64) having the corner 57 (67) as described above, the rounded surface of the corner 57 is the belt as illustrated in FIG. 58 interferes with the slidable contact side edge 59 of the belt 58, which affects the wear of the end face of the belt 58, and causes a problem that the life of the belt 58 is reduced. In other words, the rounded surface of the corner 57 is a very small rounded surface, but the sliding contact side edge 59 of the belt 58 having a substantially right-angled edge is worn by being always in sliding contact with the corner 57. End up.
Accordingly, an object of the present invention is to solve the above-mentioned problems, and a good transmission belt capable of preventing interference between the sliding contact side edge of the belt and the flange base portion and reducing belt end face wear. Is to provide a pulley.
[0006]
[Means for Solving the Problems]
An object of the present invention is a transmission belt pulley having a flange for preventing belt detachment on at least one side edge of a pulley outer peripheral portion for hanging a belt,
The inner surface of the flange is continuously formed in the circumferential direction, and has a recess that escapes contact with the sliding contact side edge of the belt ,
When the belt is in contact with the flange, only the middle part of the belt thickness is in contact with the flange .
[0007]
Preferably, the recess is provided in at least one of the inner surface side of the flange and the outer peripheral surface side of the pulley outer peripheral portion.
That is, according to the above configuration, the curvature of the corner can be increased, and the corner can be prevented from hitting the sliding contact side edge of the belt.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a transmission belt pulley according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a partial cross-sectional view of an idler pulley 1 according to the first embodiment of the present invention, and FIG.
[0009]
The idler pulley 1 includes a substantially cylindrical pulley outer peripheral portion 4 manufactured by cutting, casting, sintering, etc., and the pulley outer peripheral portion 4 fitted to the outer periphery of the bearing 2 has flanges on both side edges. 3 and 3, and a belt winding groove is formed between the flanges 3 and 3. The belt winding groove has a width slightly larger than the width of the belt 8 to be hung, and the bottom of the groove is a flat belt winding peripheral surface 5 which is the outer peripheral surface of the pulley outer peripheral portion 4.
In addition, the corners where the inner side surfaces 6 and 6 of the flanges 3 and 3 intersect the belt winding peripheral surface 5 of the pulley outer peripheral portion 4 are in contact with the sliding contact side edge 9 of the belt 8. Recessed recesses 7 are formed respectively.
[0010]
As shown in FIG. 2, the recess 7 is a groove continuously formed in the inner root portion of the flange 3 along the circumferential direction of the pulley outer peripheral portion 4, and the inner surface 6 of the flange 3 and the belt winding peripheral surface. 5 is formed with a curved surface having a large curvature that is smoothly continuous so as not to have a corner or a step. The recess 7 is recessed on the inner surface 6 side of the flange 3, and has a cross-sectional shape that is recessed in the axial direction from the contact portion 6 a of the inner surface 6 of the flange 3 with respect to the belt 8. That is, in FIG. 2, there is a recess 7 at a position recessed leftward in the axial direction from the extension line A of the inner surface 6 of the flange 3.
[0011]
Further, the height TR from the belt winding peripheral surface 5 to the outer peripheral end 7a of the recess 7 is set lower than the thickness of the belt 8 so that the side end portion of the belt 8 does not enter the recess 7. The Therefore, in the case of the first embodiment, since the belt 8 is a toothed belt having wavy teeth 8a as shown in FIG. 3, the belt winding peripheral surface 5 to the outer peripheral end 7a of the recess 7 are used. The height TR is set lower than the tooth height T2 of the belt 8. Furthermore, if the stress concentration in the recess 7 can be prevented, the height TR is preferably set lower than the tooth bottom height T1 of the belt 8 as shown in FIG.
[0012]
That is, a recess 7 is provided at the base portion of the flange 3 so as to escape from contact with the sliding contact side edge 9 of the belt 8, and a corner where the inner surface 6 and the outer peripheral surface 5 intersect with each other. The sliding contact side edge 9 does not interfere with the portion.
As a result, the idler pulley 1 in the first embodiment can reduce the end face wear of the belt 8 and can extend the life of the belt 8. Further, due to the presence of the recess 7, it is possible to increase the curvature of the portion where the inner surface 6 of the flange 3 and the belt winding peripheral surface 5 intersect, and the stress concentration at the flange base portion can be reduced.
In the above-described embodiment, the idler pulley 1 for the toothed belt having both flanges has been described. However, the present invention is not limited to this, and a pulley having only one flange, Of course, the present invention can be applied to a pulley for a transmission belt such as a drive pulley (for example, a V belt or a poly V belt). It goes without saying that the shape of the recess may take various shapes based on the gist of the present invention.
[0013]
FIG. 4 is a partial cross-sectional view of the idler pulley 11 according to the second embodiment of the present invention.
The idler pulley 11 includes a substantially cylindrical pulley outer peripheral portion 14 manufactured by pressing, and the pulley outer peripheral portion 14 fitted to the outer periphery of the bearing 2 has a flange 13 on one side edge. Yes. The outer peripheral surface of the pulley outer peripheral portion 14 is a flat belt winding peripheral surface 15.
[0014]
In addition, a recess 17 is formed in the corner where the inner side surface 16 of the flange 13 and the belt winding peripheral surface 15 of the pulley outer peripheral portion 14 intersect with each other to escape the contact with the edge 9 on the sliding contact side of the belt 8. Has been.
The recess 17 is a recess that is continuous in the circumferential direction of the pulley outer peripheral portion 14, and has a large curvature that smoothly continues without having an angle or a step with respect to the inner surface 16 of the flange 13 and the belt winding peripheral surface 15. It is formed by a curved surface. Similarly to the recess 7 of the first embodiment, the recess 17 is provided on the inner surface 16 side of the flange 13.
[0015]
Therefore, the idler pulley 11 of the second embodiment can reduce the end face wear of the belt 8 and extend the life of the belt 8, similarly to the recess 7 of the first embodiment.
Further, the presence of the recess 17 makes it possible to increase the curvature of the portion where the inner side surface 16 of the flange 13 and the belt winding peripheral surface 15 intersect, so that the stress concentration at the flange base portion can be alleviated and the press The bending radius at the time of processing becomes large and press processing becomes easy.
Further, in the idler pulley 11 of the second embodiment, the recess 17 is integrally formed simultaneously with the flange 13 by press working, so that the machining cycle time is not increased and the manufacturing cost is not increased due to an increase in the number of machining steps. .
[0016]
FIG. 5 is an enlarged cross-sectional view of a main part of the pulley outer peripheral portion 24 according to a reference example of the present invention.
In the pulley outer peripheral portion 24, a recess 27 is formed in a corner portion where the inner surface 26 of the flange 23 and the outer peripheral surface 25 of the pulley outer peripheral portion 24 intersect with each other so as to escape the contact with the edge on the sliding contact side of the belt. However, it is formed not on the inner surface 26 side of the flange 23 but on the belt winding peripheral surface 25 side, and is positioned on the inner peripheral side with respect to the extension line B of the belt winding peripheral surface 25.
[0017]
FIG. 6 is an enlarged cross-sectional view of a main part of the pulley outer peripheral portion 34 according to the third embodiment of the present invention.
In the pulley outer peripheral portion 34, there is a recess 37 that is recessed at a corner where the inner surface 36 of the flange 33 and the outer peripheral surface 35 of the pulley outer peripheral portion 34 intersect so as to escape the edge of the belt on the sliding contact side. The outer circumferential surface 35 of the flange 33 and the outer circumferential surface 35 of the pulley outer peripheral portion 34 are formed obliquely, and are extended outside the extension line A of the inner side surface 36 of the flange 33 and extended from the belt winding circumferential surface 35. It is located on the inner peripheral side from B. When forming a complicated shape such as the recesses 27 and 37, the recesses 27 and 37 are formed by, for example, forming the pulley outer peripheral portions 24 and 34 by sintering or casting (including die casting). The increase in the manufacturing cost due to can be suppressed.
[0018]
【The invention's effect】
As described above, according to the transmission belt pulley of the present invention, the corner where the inner surface of the flange and the outer peripheral surface of the pulley intersect with each other escapes from the contact with the edge on the sliding contact side of the belt. A recess is formed.
Therefore, since the sliding contact side edge of the belt having a substantially right-angled edge does not interfere with the flange base portion, the belt end face wear can be reduced and the life of the belt can be extended. Further, due to the presence of the recess, the curvature of the portion where the inner surface of the flange intersects with the belt winding peripheral surface can be increased, and the stress concentration at the flange root portion can be reduced.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of an idler pulley according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of the idler pulley shown in FIG.
3 is a longitudinal sectional view of the belt shown in FIG. 2. FIG.
FIG. 4 is a partial cross-sectional view of an idler pulley according to a second embodiment of the present invention.
FIG. 5 is an enlarged cross-sectional view of a main part of a pulley outer peripheral portion according to a reference example of the present invention.
FIG. 6 is an enlarged cross-sectional view of a main part of a pulley outer peripheral portion according to a third embodiment of the present invention.
7A and 7B are cross-sectional views of a main part of a conventional flat belt pulley, in which FIG. 7A is a cross-sectional view of a pulley manufactured by cutting or the like, and FIG. 7B is a cross-sectional view of a pulley manufactured by pressing.
FIG. 8 is an enlarged cross-sectional view of a main part showing a relationship between a conventional pulley and a belt.

Claims (1)

In a pulley for a transmission belt provided with a flange for preventing belt detachment on at least one side edge of a pulley outer periphery for hanging the belt,
The inner surface of the flange is continuously formed in the circumferential direction, and has a recess that escapes contact with the sliding contact side edge of the belt ,
When the belt contacts the flange, only the middle part of the belt thickness contacts the flange .

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