JPH0747982B2 - V belt transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a V-belt transmission device, and more particularly to a V-belt transmission device applied to a transmission device in which a maximum torque that is several times the steady torque is generated at startup. Regarding

[Conventional technology]

Conventionally, a V-belt transmission device has been widely used as a transmission winding device.

In this V-belt transmission, the tension on the belt tension side increases as the load torque increases, and at this time, the V
In addition to the advantage that the power transmission is secured by increasing the apparent friction coefficient of the belt, it is widely used as various rotary power transmission devices because of its various advantages such as high quietness and compactness.

[Problems of conventional technology]

By the way, when the V-belt transmission device is used in a transmission device in which a maximum torque which is several times the steady torque is generated at the time of starting, when the tension-side V-belt bites into the groove of the V-pulley due to the torque that sharply rises at the time of starting. At the same time, the amount of slack on the slack side increases, so the V belt floats above the V pulley,
The wrapping length around the pulley is momentarily reduced, and as a result, the belt easily slips, and a large noise is generated due to the slip. There were various problems such as impairing the useful life.

However, in order to cope with such a stress, it is possible to match the V belt with the maximum load and increase the width and thickness, but in this case, the V belt applied to the size of the V belt with respect to the normal torque is There is a drawback that it becomes very large and the overall size of the device cannot be sufficiently reduced.

[Problems to be Solved by the Invention]

In view of the above-mentioned drawbacks, the present invention can sufficiently cope with the maximum stress regardless of the size of the V-belt with respect to the steady torque. Therefore, it is possible to reduce the size of the winding transmission device in which such torque is generated without difficulty. The purpose is to provide a V-belt transmission that can be achieved.

[Technology that has solved the problem]

That is, in the V-belt transmission device of the present invention, a V-belt and a high-modulus pressing belt having an inner peripheral length slightly shorter than the V-belt outer peripheral length are overlapped and wound between two or more V-pulleys, and the V-belt transmission device having the high-modulus It is characterized in that the initial tension is applied only to the pressing belt.

[Action]

In the present invention, as shown in FIG. 1, a V-belt 2 having a high modulus is wound between two or more V-pulleys 1A and 1B, and an outer peripheral length of the V-belt 2 is provided thereon as shown in FIG. The high-modulus pressing belt 3 having a slightly longer inner peripheral length is superposed and mounted, and in this state, only the pressing belt 3 is applied with initial tension.

The initial tension is applied by tensioning the pressing belt 3 by adjusting the shafts of the V pulleys 1A and 1B, and by tensioning the tension pulley 4 to the pressing belt 3 as shown in FIG. With this, the initial tension may be applied.

In the above, the V belt 2 is an ordinary V belt 2 in which an elastic body such as rubber or polyurethane is embedded with a core body such as glass fiber or Kevlar, and the pressing belt 3 is formed of an elastic body such as rubber or polyurethane. In addition to flat belts with embedded cores such as glass fiber and Kevlar,
An endless annular steel belt or a belt made of a high modulus resin film is used.

When the initial tension is applied when the inner peripheral length of the high-modulus pressing belt 3 is longer than the outer peripheral length of the V-belt 2, the tension is applied to the V-belt 2 and the pressing-belt 3 retains the tension on the loose side. I can't take charge of it.

If the inner peripheral length of the pressing belt 3 is extremely shorter than the outer peripheral length of the V belt 2, the inward expansion of the V belt 2 in FIG. Becomes

Therefore, in consideration of the above, the length of the pressing belt 3 is set such that the inner peripheral length thereof is somewhat longer than the outer peripheral length of the V belt 2.

As shown in FIG. 3, when the number of V pulleys is three or more, there is almost no contact with the inside of the V belt 2 on the opposite side, so the length is limited more than that using the above two V pulleys. Can be reduced.

In this invention, the initial tension of the V-belt 2 is the first
As is clear from FIGS. 3 to 3, it is zero, and the initial tension is exclusively taken up by the pressing belt 3.

Next, when a load torque is applied, tension is applied to the tension side of the V-belt 2 according to the load torque as shown in FIG.

Therefore, nothing is applied to the V-belt 2 other than the tension required for power transmission, and the V-belt 2 has only the function of power transmission.

On the other hand, since the pressing belt 3 is simply overlapped with the outer circumference of the V-belt 2, it is possible to slip between them, and when driving is started, the frictional force between the two causes the V-belt 2 to rotate together. Becomes Therefore, the pressing belt 3
The initial tension is applied to, but it is not responsible for power transmission at all, and is solely responsible for retaining the tension on the loose side.

As described above, the V-belt 2 is responsible for only power transmission and the presser-belt 3 is only responsible for holding the initial tension. Therefore, when the load torque increases, the swelling of the V-belt 2 toward the inner side on the loose side increases. The tension on the slack side never drops.

Further, since the V-belt 2 is pressed by the pressing belt 3 from the outside and is deformed so as to be wound around the V-pulleys 1A and 1B, the wrapping angle with respect to the V-pulley is also increased, and therefore, even with a weak pressing force, a considerably high load transmission is achieved. It is possible without slip.

Since the V-belt 2 and the pressing belt 3 according to the present invention are wound around the V-pulleys 1A and 1B so as not to be separated from the V-pulley, the V-belt 2 and the pressing belt 3 are provided on the rear surface of the V-belt 2 and the inner surface of the pressing belt 3 as shown in FIG. Concavo-convex strips 4A and 4B may be provided which are fitted in a male-female relationship with each other.

It should be noted that the concavo-convex lines 4 and 4 may be a plurality of lines as shown in FIG.

In addition to the above-described fitting structure, as shown in FIG. 7, V pulleys 1A and 1B may be provided with flanges 1'and 1'of heights capable of receiving both belts 2 and 3, respectively.

〔Example〕

 Next, an embodiment of the present invention will be described.

A V-belt 2 made of polyurethane with Kevlar fibers embedded as a tensile strength member and specified in Table 1 is loosely wound around a drive V-pulley 1A with a movable shaft center and a driven V-pulley 1B with a fixed shaft center. The inner circumference is slightly longer than the outer circumference of the V-belt 2, and a polyurethane flat belt in which Kevlar fibers are embedded as a tensile strength member is pressed as the holding belt 3 to loosely wind the drive V-pulley 1A. The initial tension was applied only to the belt 3 which was wound and overlapped.

Table 1 Table 2 V-belt specifications Holding belt specifications Outer peripheral length 706 mm Inner peripheral length 700 mm Top width 7 mm Width 7 mm Belt thickness 5.3 mm Thickness 1.5 mm With this initial tension applied, as shown in Fig. 2, V belt 2 is on the tension side. Then, the slack side bulged inward by about 10 mm, and the pressing belt 3 became in a tense state.

When the drive pulley 1A was rotated in this state, the inward bulge on the tension side of the V-belt 2 instantly moved to the slack side, and the state shown in FIG. 4 was obtained.

[Performance test of examples]

The V-belt transmission according to the above-mentioned embodiment is applied with four levels of initial tension, and the drive pulley 1A is rotated at 2850 rpm.
A load torque was gradually applied to the driven pulley 1B, and the load torque at the time when the V-belt transmission caused a 4% slip was read to obtain a graph shown in FIG.

In FIG. 8, in Comparative Example 1, only the V-belt 2 equivalent to that in Example was used, and the drive pulley 1A was adjusted without the pressing belt 3 to read the 4% slip generation torque when the initial tension was varied by four levels. It is a thing.

As is clear from FIG. 8, it was confirmed that the Examples had excellent slip resistance in any initial tension state.

〔effect〕

As described above, according to the V-belt transmission device of the present invention, the power transmission function and the initial tension holding function are shared by the V-belt 2 and the pressing belt 3, and even when the load torque suddenly increases. The tension of the belt 3 increases and V
Since the slippage of the belt 2 can be effectively prevented, it is possible to safely specify a transmission device in which the maximum torque which is several times the steady torque is generated at the time of starting.

Therefore, unlike the conventional case, it is not necessary to use a wider belt than necessary, and the apparatus can be easily made compact and lightweight.

[Brief description of drawings]

1 to 3 are side views of an embodiment of the present invention, FIG. 4 is a side view of another embodiment, and FIG. 5 is a sectional view of a main part of a V pulley of the embodiment, FIGS. 6 and 7. FIG. 8 is a sectional view of a main part of a V-pulley of another embodiment, and FIG. 8 is a graph showing the relationship between the initial tension and the slip of the embodiment.

Claims (3)

[Claims] 1. A V-belt and a high-modulus pressing belt having an inner peripheral length slightly shorter than the outer peripheral length of the V-belt are overlapped between two or more V-pulleys, and only the high-modulus pressing belt is initially wound. V characterized by being added with tension
Belt transmission. 2. The V-belt transmission device according to claim 1, wherein the V-pulley is provided with a flange having a height capable of receiving both the V-belt and the high-modulus pressing belt. 3. The V-belt transmission device according to claim 1, wherein a concavo-convex strip is formed on the rear surface of the V-belt and the inner surface of the high-modulus pressing belt so as to be fitted in a male-female relationship with each other.