JPH01229169A - Pulley for v-ribbed belt - Google Patents

Abstract

PURPOSE:To effectively prevent warp due to a difference in belt surface pressure in the cross direction by making the opposite intersecting angle between opposite side walls of a recessed groove larger than at the outer lines than that at the central line. CONSTITUTION:A V-ribbed belt 3 used has an intersecting angle alpha of 40 deg. between each projection and three and four streak projections 4. The sectional shaped of recessed grooves 2 of a pulley 1 for the V-ribbed belt corresponding to the projection is such that an opposite angle theta1 between side walls 2A, 2B of the central groove and opposite angles theta2 between side walls 2A, 2B of both side grooves are let be theta1<theta2 and theta2-theta1=0 deg.-6 deg.. Accordingly, the streak projections 4 of the V-ribbed belt 3 can be engaged with the recessed grooves 2 more smoothly at the side end portions, so that even if there is unequal distribution of extensional rigidity, reaction is reduced at the side end portions so as to prevent the generation of warp.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a pulley for a V-ribbed belt.

[Conventional technology]

Conventionally, a wide V-ribbed belt with multiple stripes in the circumferential direction has been used as a transmission heald (for example, in Japanese Patent Application Laid-Open No. 62-113
No. 940).

This V-ribbed belt has the same effect as if multiple ■bells 1 were wrapped in parallel at the same time, so it has good transmission efficiency, and it also requires less maintenance and management than when multiple ■・＼ruts are wound. It has the advantage of being easy and particularly suitable for small-sized transmissions.

[Problems with conventional technology]

However, in a transmission device using a V-ribbed belt as described in (b), the longitudinal elongation rigidity of the heald is large at the center of the heald and becomes small at the side ends during power transmission.

Therefore, as shown in FIG.
Compared to the surface pressure F of
This has the drawback of causing slippage between the two, resulting in a reduction in power transmission performance and the generation of slip noise.

In order to solve this problem, for example,
It has also been proposed to make the outer peripheral surface of the pulley for a V-ribbed belt a concave curved surface to follow the warp of the V-ribbed belt, as disclosed in No. 00657 or JP-A-59-190570. There was a problem that could not be solved satisfactorily, such as the warping of the belt when the pulley was engaged with the pulley due to the uneven distribution of elongation stiffness in the longitudinal direction.

That is, since the surface pressure of the side edge A2 of the hel I is smaller than that of the center part AJ, the protrusion AJ of the side ◇ze; part A2 is sufficiently inserted into the concave groove of the ribbed helt boot. This causes a reaction force against the V-ribbed belt, causing it to warp.

(Problems to be solved by the invention) This invention is designed in view of the problems listed in -1- -J¥? ;Node 1 at t1
Our objective is to provide a pulley for VIJ Zotoheru 1~ that effectively prevents warping due to the difference in heald surface pressure l + force direction and enables more efficient transmission despite its 11 configuration. This was done as a.

[Technology to solve problems]

That is, the pulley for Ribto Helt I of the present invention has a plurality of grooves on the outer circumferential surface that engage with a plurality of circumferentially continuous convex lines formed on the inner surface of the V RibtoHelt, and the plurality of grooves fit together with each other. The opposing intersection angles formed by the opposing side walls of each of the four l^1 in the outer row are larger than those in the center row (
There are 11 signs of what will happen.

[Function] Generally, in a transmission device using a V-ribbon I-
The cross-sectional shape of the convex line formed on the inner surface of the ribbed helt and the corresponding concave groove of the ribbed helt pulley is ■・＼
The opposite side wall 2A of the groove 2 on the pulley 1 side, as shown in FIG.

2[3's intersection angle θ1. θ2 is l; compared to the intersecting angle α of the convex ridges 4 of the Risotchelt 3 at the time of one song,
Also, it is normal that θ1...θ.

Therefore, as shown in Fig. 7, if there is an unequal distribution in the elongation stiffness in the heald longitudinal direction in the l-+ direction in ■Reso[・Hel)・, the reaction force f will also be unequally distributed accordingly, and this As mentioned above, this causes the heald to warp.

In order to make this reaction force f uniform in the rl+ direction of the pulley, as shown in Fig. 2 (a) and (b), Crossing angle θ
1. The outer end θ2 is defined as θ2.

As a result, the convex rib of the ribbed helt is easier to fit smoothly into the groove of the pulley as it approaches the side edge, and even if there is an uneven distribution of the extensional stiffness, the reaction force r at the side edge is It should be small and prevent warping.

The angle θ1 of the opposing wall surface of the concave groove of the pulley is made larger by about 2° to 4° than that of the center portion, although it differs depending on the pulley diameter, transmission horsepower, gear l-lll, etc.

〔Example〕

Next, this invention will be explained in detail.

■Prepare ribtoher I and the intersecting angle of each protrusion α-400 and the number of protrusions of 3 and 4, as shown in Figure 2 (a) and (l) as pulleys to be wound around. The opposing angle θ of the groove side walls in the center and the opposing angle θ2 of the groove side walls on both sides are as follows.
Prepare a boolean with θ1 < θ7, and θ, -θ, -0° to 6°, and use the test equipment shown in Figure 3 to determine the transmission efficiency, and the test equipment shown in Figure 4 to determine the winding efficiency. The service life was tested.

The transmission efficiency testing device has a diameter of 45 ψmm to 100 ψ.
m lll's boo January 0,11... Le I3, 31
1 drive, [J side pulley 10 at 3500 rpm, and a dead load of 80 kgf applied to the driven side 11.The test device for the service life was a drive driven pulley with a diameter of 120ψmm and a diameter of 4
A 5φmm idler pulley 12 is arranged as shown in FIG. 4, and a 85kgf
A set weight is added to the idler pulley 12, and the drive pulley 10 is driven at 490 rpm.

As a result of the above test, it was confirmed that the transmission efficiency is better in the range of θ2-θ=2° to 4°, and the smaller the diameter of the pulley, as shown in FIG.

Furthermore, as shown in FIG. 6, it was confirmed that the life ratio was within the range of θ2-θ1-2° to 4°, and that the smaller the diameter, the better, as was the case with the transmission efficiency.

〔effect〕

As explained above, when the ribbed helt wound under constant tension is bent along the pulley, the concave groove of the pulley for the V-ribbed helt is shaped to match the deformation of the rib protrusion caused by this curving. Since the intersecting angle of the opposing walls is adjusted, there is little variation in the reaction force r caused by the winding 11; , the transmission efficiency and lifespan are significantly the same.

In addition, in this invention, (1) the ribtoherd may be the same as the conventional one, so it is easy to implement, and has a divine practical effect.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the operation of this invention, and FIG. 2 (A). (B) is a sectional view of the main part of the embodiment, FIGS. 3 and 4 are explanatory diagrams of the test equipment, FIGS. 5 and 6 are graphs showing the test results, and the seventh row is an explanation of the conventional example. In the figure, 7/m θ7=θ2 2m'? '2ffi θ7ri6 (a) Strawberry, ♀7ken7← (to) 0 [Yes] Chicken〈 \ Q. Female eating ceremony ← N

Claims (1)

[Claims] (1) The V-ribbed belt has a plurality of concave grooves on its outer circumferential surface that engage with a plurality of circumferentially continuous protrusions formed on the inner surface of the belt, and the opposite side walls of each of the plurality of concave grooves are A pulley for a V-ribbed belt, characterized in that the opposing crossing angles formed by the pulleys in the outer row are larger than those in the center row.