JPH02146352A - V belt transmitting device - Google Patents

Abstract

PURPOSE:To attain the compactness of a transmitting device coping sufficiently even with maximum stress by overlapping a V belt with a retaining belt of high modulus, having its internal peripheral length slightly shorter than the peripheral length of said V belt, wound between two or more V pulleys and additionally applying initial tension only to said retaining belt of high modulus. CONSTITUTION:A V belt 2 of high modulus is wound linking between V pulleys 1A, 1B, and the belt 2 mounts to its upper overlapping a retaining belt 3 of high modulus with its internal peripheral length shortly longer than the peripheral length of the V belt 2. Next applying load torque, tension is applied in accordance with the load torque to a tensile side of the V belt 2. While the retaining belt 3 is rotated together with the V belt 2. Thus, the V belt 2 and the retaining belt 3 share a burden of power transmitting and initial tension holding functions, even when the load torque suddenly increases, the retaining belt 3 increases its tension effectively preventing a slip of the V belt 2, and it is able to be safely used even for a transmitting device such as generating maximum torque several times the steady torque in the time of starting. In this way, the device attains its compactness and lightness of weight.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a V-belt transmission device, and more specifically to a V-belt transmission device that is applied to a transmission device that generates a maximum torque several times the steady torque at startup. Regarding.

(Prior Art) A V-belt transmission device has been widely used as a winding device for transmission.

In this V-belt transmission device, as the load torque increases, the tensioned side of the belt becomes tense, and the V-belt
Belts have the advantage of ensuring transmission power due to an increase in the coefficient of friction, as well as being quiet and compact, making them widely used in various rotational transmission devices. There is.

[Problems with conventional technology]

By the way, when the V-belt transmission device described above is used in a transmission device that generates a maximum torque several times the steady torque at startup, if the tension-side V-belt digs into the groove of the V-pulley due to the torque that rapidly increases during startup. At the same time, the amount of slack on the loose side increases, so the V-belt rises above the V-pulley.
The length of the belt wrapped around the pulley momentarily decreases, and as a result, the belt tends to slip, which has the disadvantage of generating loud abnormal noises.Furthermore, extremely unreasonable stress is applied to the belt, causing damage to the belt. There were various problems such as a loss of service life.

However, in order to cope with such stress, it is possible to increase the width and thickness of the V-belt to match the maximum load, but in this case, the V-belt that is applied to the size of the V-belt for the normal torque may be The disadvantage is that the device is very large and the overall device cannot be made sufficiently compact.

[Problem to be solved by the invention]

In view of the above-mentioned drawbacks, the present invention makes it possible to sufficiently cope with the maximum stress even though the size of the V-belt is large enough for steady torque, thereby easily downsizing the wrap-around transmission device that generates such torque. The purpose of this invention is to provide a V-belt transmission device that can achieve the desired results.

[Technology that led to solving the problem]

That is, in the V-belt transmission device of the present invention, a V-belt and a high-modulus presser belt whose inner circumference is somewhat shorter than the outer circumference of the V-belt are wound overlappingly between two or more V-boots. This is characterized in that initial tension is applied only to the holding belt.

[Effect]

In this invention, as shown in FIG. 1, a high modulus V-belt 2 is wound between two or more pulleys IA and IB, and as shown in FIG. High modulus presser belts 3 having a somewhat longer inner circumferential length are mounted one on top of the other, and in this state, initial tension is applied only to the presser belts 3.

This initial tension is applied by adjusting the axes of the pulleys IA and IB to tension the presser heald 3, and also by pressing the tension bobbin 4 against the presser heald 3 as shown in Figure 3. , a configuration may be adopted in which initial tension is added by this.

In the above, the V-belt 2 is a normal V-belt 2 in which a core material such as glass fiber or Kevlar is embedded in an elastic material such as rubber or polyurethane, and the presser belt 3 is made of an elastic material such as rubber or polyurethane. In addition to flat belts with embedded cores such as glass fiber and Kevlar,
Endless ring-shaped steel belts and high-modulus resin film belts are used.

Note that if the inner circumference of the high-modulus presser belt 3 is longer than the outer circumference of the V-belt 2, when initial tension is applied, the tension will be applied to the V-belt 2, and the presser belt 3 will have a function of maintaining tension on the slack side. Uke will no longer be able to hold it.

Furthermore, if the inner circumference of the presser belt 3 is extremely shorter than the outer circumference of the V-belt 2, the inward bulge of the V-belt 2 in FIG. becomes.

Therefore, in consideration of the above, the length of the presser belt 3 is such that the inner circumferential length thereof is somewhat longer than the outer circumferential length of the V-belt 2.

In addition, when there are three or more V pulleys as shown in Figure 3, there is almost no contact with the inside of the opposite V-belt 2, so the length limit is greater than the case using two V pulleys as described above. You can do less.

In this invention, the initial tension regarding the V-belt 2 is the first
As is clear from FIGS. 3 to 3, the initial tension is zero, and the initial tension is held solely by the holding belt 3.

Next, when a load torque is applied, as shown in FIG. 4, tension is applied to the tension side of the V-belt 2 according to the load torque, causing tension as shown in the figure.

Therefore, no tension other than that required for transmission is applied to the V-belt 2, and the receiver has only the function of transmitting power.

On the other hand, since the presser belt 3 is simply overlapped on the outer periphery of the V-belt 2, it is possible to slide between them, and when the drive starts, it rotates with the V-belt 2 due to the friction between them. becomes. Therefore, the presser heald 3 only has an initial tension applied thereto, but does not transmit power at all, and the receiver only has the function of holding tension on the slack side.

As described above, the V-belt 2 only transmits power, and the presser belt 3 only maintains the initial tension, so when the load torque increases, the slack side of the V-belt 2 swells inward. As a result, the tension on the slack side does not decrease at all.

Furthermore, since the V-belt 2 is pressed from the outside by the presser belt 3 and is deformed so as to wrap around the V-pulleys IA and IB, the wrapping angle around the V-pulleys also becomes large, and therefore, even with a weak pressing force, the force is considerably high. Load transmission is also possible without slipping.

In this invention, the V-belt 2 and the holding belt 3 are wrapped around the V-pulleys IA and IB in an overlapping manner, so that the heald 2 is wrapped around the V-pulleys IA and IB in order to prevent them from coming off the V-pulleys as shown in FIG.
Concave and convex strips 4A that fit into the back surface and the inner surface of the presser belt 3 without any #I male amount relationship.

4B may be provided.

Incidentally, the uneven strips 4.4 may be formed in a plurality of strips as shown in FIG.

In addition to the fitting structure described above, flanges 1' and 1° may be provided at the v-boots IJIA and IB with a height capable of receiving both healds 2.3, as shown in FIG.

〔Example〕

Next, embodiments of the invention will be described.

V-belt 2, which is made of polyurethane with Kevlar fiber embedded as a tensile strength material and has specifications in Table 1, is loosely wrapped around the drive V-pulley IA whose shaft core is movable and the driven pulley IB whose shaft core is fixed, and then The inner circumference is slightly longer than the outer circumference of the V-belt 2, and a flat belt made of polyurethane with Kevlar fibers embedded as a tensile strength member is used as the holding belt 3, which is loosely wound around the driving force. Initial tension was applied only to the belts 3 that were moved and wrapped around each other.

Table 1 Table 2 One! 5. Photographed on the ground.
706 members Inner circumference length 700mm Upper width
7 Hoho Width 7 - Belt Thickness 5.3 Dragon Thickness 1.5 Hoho 1 The state in which this initial tension is applied is as shown in Figure 2, V-belt 2
Both the tension side and the slack side swelled inward by about 10 mm, and the presser belt 3 became under tension.

When I rotated the drive boob IJIA in this state,
The inward bulge on the tension side of the V-belt 2 instantly shifted to the slack side, resulting in the state shown in FIG. 4.

[Performance test of example]

According to the above example, ■ Apply initial tension varying in four levels to the belt transmission, rotate the drive pulley IA at 2850 rpm + W, gradually apply load torque to the driven boob IJ I B, The load torque at the time when % slip occurred was read and the graph shown in FIG. 8 was obtained.

In Fig. 8, Comparative Example 1 uses only the V-belt 2 that is the same as the Example, and reads the 4% slip generation torque when the drive pulley IA is adjusted without the presser belt 3 and the initial tension is varied at four levels. It is something.

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

〔effect〕

As explained above, according to the belt transmission device of the present invention, the power transmission function and the initial tension holding function are shared between the V-belt 2 and the presser heald 3, so that even when the load torque suddenly increases, the The tension of belt 3 increases and V
Since slipping of the belt 2 can be effectively prevented, it is possible to safely use a transmission device that generates a maximum torque several times the steady torque at startup.

Therefore, there is no need to use an unnecessarily wide belt as in the past, and the device can be made more compact and lighter.

[Brief explanation of the drawing]

1 to 3 are side views of an embodiment of the present invention, FIG. 4 is a side view of another embodiment, FIG. 5 is a sectional view of essential parts of the V-pulley of the embodiment, and FIGS. 6 and 7 The figure is a sectional view of a main part of a V-boot according to another embodiment, and FIG. 8 is a graph showing the relationship between initial tension and slip in the embodiment. T/En/A, no Bzv Ahri? : v to 1st 3 2tVt vert T2 figure T5(fJ γotm 73 figure 74m T'l(fEJ

Claims (3)

[Claims] (1) A V-belt and a high-modulus presser belt whose inner circumference is somewhat shorter than the outer circumference of the V-belt are wrapped between two or more V pulleys, and the initial tension is applied only to the high-modulus presser belt. A V-belt transmission device characterized by being added. (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 presser belt. (3) The V-belt transmission device according to claim 1, wherein the back surface of the V-belt and the inner surface of the high-modulus presser belt are formed with concave and convex stripes that fit in a male-female relationship with each other.