JPH0777245A - Driving device of belt for power transmission - Google Patents

Abstract

PURPOSE:To heighten the durability of a belt by making improvements in grip force between the belt and a pulley, while relaxing the core stress of a belt end and checking such a trouble phenomenon as separating the belt from an adhesive rubber layer. CONSTITUTION:This is a driving device of a power transmission belt consisting of a power transmission belt provided with at least one belt groove strip part 9 extending the longitudinal direction of this belt, on the bottom part of a compressed rubber layer, and a pulley 15 housing this belt, and a tilt angle of the belt groove strip part 9 is equal to an angle of a pulley projecting strip part 18 to be fitted with this groove strip part 9 or larger than that otherwise, and simultaneously a tilt angle of a belt outer side 12 is made smaller than that of a pulley groove part outer side 19 the other way. In addition, the device is so constituted that an angle differential between the belt groove strip part 9 and the pulley projecting strip part 18 is made smaller than that between the belt outer side 12 and the pulley groove part outer side 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a power transmission belt, and more particularly, to a power transmission belt having a good gripping force between the belt and the pulley, a small slip, and an excellent transmission force. A drive device.

[0002]

2. Description of the Related Art Generally, in a power transmission V-belt, a core wire made of a rope having low elongation and high strength is embedded in an adhesive rubber layer,
In addition, a stretched rubber layer and a compressed rubber layer in which short fibers are oriented and mixed in the transverse direction are laminated on the lower portion, and the outer peripheral portion is covered with a canvas with rubber. However, when the tension of the belt increases, the gripping force with the pulley is limited, and slipping easily occurs. Therefore, as disclosed in U.S. Pat. No. 2,471,969, a belt drive device in which one belt groove portion is provided in the compressed rubber layer and is engaged with the pulley groove portion and the pulley protrusion portion. Was proposed.

[0003]

However, in this belt driving device, the angle difference between the belt groove portion and the pulley protrusion portion is equal to the angle difference between the belt outer surface and the pulley groove outer surface. Therefore, generally, the stress distribution of the belt core wire during driving becomes larger at the end portion than at the belt central portion. Further, this tendency is promoted by the deformation of the central portion into a concave shape as the belt is worn, resulting in the failure that the core wire at the end portion is separated from the adhesive rubber layer. The present invention solves such a problem, and enhances the gripping force between the belt and the pulley, relaxes the core stress at the belt end portion, and prevents the failure phenomenon of peeling from the adhesive rubber layer to prevent the belt. The purpose is to increase the durability of.

[0004]

That is, the feature of the present invention is that an expanded rubber layer is arranged above an adhesive rubber layer in which a core wire is embedded, and a compressed rubber layer is arranged below the adhesive rubber layer. A power transmission belt having at least one belt groove portion extending along the longitudinal direction of the belt at the bottom of the belt, and a pulley having a ridge portion for accommodating the belt and fitting with the belt groove portion. In the drive device of the transmission belt,
The inclination angle of the belt groove portion is equal to or larger than the angle of the pulley protrusion portion fitted with the groove portion, the inclination angle of the belt outer surface is smaller than the inclination angle of the pulley groove outer surface,
In addition, there is provided a drive unit for a power transmission belt in which an angle difference between the belt groove portion and the pulley protrusion portion is smaller than an angle difference between the belt outer surface and the pulley groove outer surface.

[0005]

In such a power transmission belt driving device, since at least one belt groove portion is supported by the pulley protrusion, the grip force of the belt can be obtained and the lateral pressure on the outer surface of the belt can be reduced. Can be reduced. Moreover, when the belt is fitted into the pulley, the central part of the belt is deformed into a convex shape,
The core stress at the belt end portion is relaxed as compared with the central portion, and as a result, the core wire at the belt end portion is less likely to be peeled off, and the cutting of the belt can be prevented.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partial cross-sectional perspective view of a power transmission belt according to the present invention. According to this, the structure of the belt 1 is a rubber material such as NR, SBR, CR, H-NBR, or a mixture thereof. A core wire 3 made of a rope with low elongation and high strength such as polyester fiber or aramid fiber is embedded in an adhesive rubber layer 2 made of. An expanded rubber layer 5 made of the same material as the adhesive rubber layer 2 and having an outer surface laminated with a rubberized canvas 4 is formed on the upper portion of the adhesive rubber layer 2, and a polyamide is formed on the lower portion of the adhesive rubber layer 2. ,
A compression rubber layer 7 in which short fibers 6 such as polyester, vinylon, cotton, etc. are oriented in the belt width direction is laminated and integrated.

At the center of the bottom surface of the compressed rubber layer 7, there is a belt groove portion 9 provided along the longitudinal direction and having a substantially triangular cross section. In the belt shown in FIG. 1, the belt groove portion 9
However, a plurality of belt groove portions 9 may be provided. The depth of the groove portion 9 does not reach the core wire 3, and is preferably 10 to 70% of the height from the belt bottom surface 10 to the core wire 3. The inclination angle A of the belt outer surface 12 is usually 25 to 45 °, but it may be a wide angle exceeding 50 °.

On the other hand, the pulley 15 used with this is
There is a V-groove 16 and a pulley ridge portion 18 having a substantially triangular cross section, which is raised from a bottom surface 17 thereof.
It is fitted with. In this case, the inclination angle D of the pulley protruding portion 18 is 15 to 20 °, and the inclination angle C of the pulley groove portion outer surface 19 is 15 to 20 °. Here, the inclination angle B of the belt groove portion 9 is such that the pulley protrusion portion 18 that fits into this groove portion 9 is formed.
Is equal to or larger than the inclination angle D of the above, and the inclination angle A of the belt outer surface 12 is smaller than the inclination angle C of the pulley groove outer surface 19 by 1 ° or more. Moreover, the angle difference (BD) between the belt groove portion 9 and the pulley protrusion portion 18 is smaller than the angle difference (CA) between the belt outer surface 12 and the pulley groove outer surface 19 by 1 ° or more.

Here, as shown in FIGS. 3 and 4, when the belt 1 and the pulley 15 are engaged with each other, the belt groove portion 9 and the pulley protrusion portion 18 are first fitted to each other, and further the belt 1 is engaged.
The outer surface 12 of the belt comes into contact with the outer surface 19 of the pulley groove by increasing the tension. At this time, the belt central portion 11
Becomes convex, and as a result, the surface pressure of the belt outer side surface 12 is relaxed, and the stress of the core wire 3 at the belt end portion becomes lower than that of the core wire 3 at the belt central portion 11.

Next, an example of experiment confirming the effect of the present invention will be shown below. As shown in FIG. 1, a cord made of polyester fiber rope is embedded in an adhesive rubber layer made of a chloroprene rubber composition, and an expanded rubber layer in which two layers of rubberized canvas are laminated on the upper side thereof, and another adhesive rubber layer is formed. A B-type low-edge V-belt having a compressed rubber layer on the lower side and having a belt groove having a predetermined angle in the center of the bottom was manufactured.
A chloroprene rubber composition containing short fibers was used for both the stretched rubber layer and the compressed rubber layer.

In the belt manufacturing method, two layers of rubberized canvas are wound around the mold, then the stretched rubber layer, the core wire, and the compressed rubber layer are sequentially wound, and this is heated and pressed to obtain a vulcanized belt sleeve. The belt groove portions having a predetermined angle were ground by a grinder, and further cut into a V shape by a cutter to prepare individual belts. still,
The depth of the belt groove portion was 50% of the height from the bottom surface of the belt to the core wire. The inclination angle A of the outer side surface of the belt is 18
The angle of inclination B of the belt groove was 20 °.

On the other hand, in both the drive pulley and the driven pulley used together with this, the inclination angle C of the V groove was 18 °, and the inclination angle D of the pulley protruding portion was 18 °.

Next, a diesel engine idling durability test of the belt was conducted to measure the belt slip ratio,
Belt life comparison was performed. The results are shown in Table 1. In this test method, the belt was attached to a driving pulley having a diameter of 140 mm and a driven pulley having a diameter of 80 mm on the crankshaft and the alternate shaft with an initial tension of 60 kgf, and the rotation speed of the driving pulley was 700 rpm and the driven shaft load was 1.3 at room temperature. I ran with horsepower.

[0014]

[Table 1]

As a result, the inclination angle A of the outer surface of the belt is made smaller than the inclination angle C of the outer surface of the pulley groove portion, and the inclination angle B of the belt groove portion is fitted to the groove portion 9.
It can be seen that the drive device of the power transmission belt having a larger inclination angle D than the above has a small belt slip ratio and improved belt durability.

[0016]

As described above, according to the present invention, at least 1
Since the two belt groove portions are supported by the pulley protrusions, the grip force of the belt can be obtained, the lateral pressure on the outer surface of the belt can be reduced, and when the belt is fitted on the pulley, the central portion of the belt Deforms in a convex shape, the core wire stress at the belt end portion is relaxed as compared with the central part, and the core wire peeling and cutting at the belt end portion can be prevented, and the belt life is improved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view of a power transmission belt used in a drive device for a power transmission belt of the present invention.

FIG. 2 is a cross-sectional view of a pulley used in the drive device for the power transmission belt of the present invention.

FIG. 3 is a cross-sectional view showing a fitted state of the belt and the pulley when the power transmission belt has no tension in the present invention.

FIG. 4 is a sectional view showing a fitted state of the belt and the pulley when the power transmission belt receives a tension in the present invention.

[Explanation of symbols]

 1 Power Transmission Belt 2 Adhesive Rubber Layer 3 Core Wire 5 Stretching Rubber Layer 6 Short Fibers 7 Compression Rubber Layer 9 Belt Grooves 12 Belt Outer Side 15 Pulley 16 V Groove 18 Pulley Ridge 19 Pulley Groove Outer Side

Claims (1)

[Claims] 1. An adhesive rubber layer in which a core wire is embedded, an extended rubber layer is provided on an upper portion thereof, and a compressed rubber layer is provided on a lower portion thereof, and at least one belt groove extending along a longitudinal direction of the belt is provided at a bottom portion of the compressed rubber layer. In a drive unit for a power transmission belt, which comprises a power transmission belt provided with a ridge portion and a pulley having a ridge portion for accommodating the belt and fitting with the belt groove ridge portion, an inclination of the belt groove ridge portion is provided. The angle is equal to or greater than the angle of the pulley protrusion that fits with this groove, the inclination angle of the belt outer surface is smaller than the inclination angle of the pulley groove outer surface, and the belt groove and pulley protrusion Is smaller than the angle difference between the outer surface of the belt and the outer surface of the pulley groove, the drive unit for the power transmission belt.