FI66063C - V-belt - Google Patents

Description

Ivkär ^ l M «« KOUI NEW PUBLICATION ,, n ,,

Jtga 1 J '' utlaggningsskmft oouoo • C «n Patent aytnucti.y 10 08 1934

Patent meddelat ^ ^ (51) Kv.Hu /lnt.CI.^ F 16 G 5/08 FINLAND — FINLAND (21) PauntUhakamut - Pauntanaeknlftf 773723 (22) Hakemhpilvl — AmBknlnprfaf 09.12.77 (23) Aikupkty »—09.12.77 (41) Become Public - Bllvtt offuntilg 21.06.78

Patent-) a ruktltf (44) Nlihtivftktlp «non And Monthly« Public «date. -

nttanfe. och fglltwityraton AiwttJuu »utlafd od» utUkrHUn puMIcerad 30.04.8A

(32) (33) (31) Pjrrdutty atuoiksus — BifM priorkat 20.12.76

England-England (GB) 53115/76 (71) A / S Roulunds Fabriker, Hestehaven, 5260 Odense S, Denmark-Danmark (DK) (72) Hardy Larsen, Odense, Denmark-Danmark (DK) (7A) Oy Kolster Ab (5A) V-belt - Kilrem

The invention relates to a V-belt consisting exclusively of a hydrogen zone, a pressure zone and force-transmitting cord young placed between the hydrogen zone and the pressure zone, and wherein the hydrogen zone and the pressure zone essentially comprise rubber compounds in which fibers are embedded, and in which both

Such known V-belts, described e.g. in CH 528,687, all contain one or more layers of woven or non-woven textile material in either the pressure zone or the tension zone or both, and in many cases the cord strings are embedded in a soft rubber layer between the pressures in the tension zone.

The V-belt according to the present invention is characterized in that most of the fibers embedded in the rubber compounds are oriented in a manner known per se perpendicular to the longitudinal direction of the belt and parallel to the upper and lower --- - τ ~ 2 6 5063 edge of the belt cross-section; that the ratio between the energy storage module E 'of the rubber compound, measured parallel to the main fiber direction, and the energy storage module E' measured perpendicular to the main fiber direction at the same temperature in the temperature range of 50 to 120 ° C; and that the ratio between the energy storage module E 'of the mixture and its loss modulus E ", both measured parallel to the main fiber direction and at the same temperature in the temperature range of 50 to 120 ° C, is greater than 4.5.

The above parameters E 'and E "are measured with a Rheovibron, manufactured by Toyo Baldwin & Co. (UK), on a test piece made of a rubber compound filled with these fibers, and to a certain extent simplifying, the quantity E' represents the stiffness of the substance in the measuring direction and E" indicates the internal damping in the substance when a swing force is applied to one end of the test piece.

Ko. the values are more or less temperature-dependent and generally decrease with increasing temperature within said range, chosen to cover the belt temperatures expected in normal use.

It follows from the relationships characteristic of the invention between the dynamic properties of the fibrous rubber material that the finished belt acquires a very high stiffness in the transverse direction, i. parallel to the direction in which the majority of the fibers mixed with the material are oriented, combined with a much lower stiffness, i. with greater flexibility, along the length of the belt. In addition, the internal damping of the belt material is small. As a result, the belt can withstand considerable specific surface pressure at the force-transmitting contact surfaces which are against the pulleys of the pulleys, and can therefore transmit high powers. The low damping of the material reduces the generation of heat in the belt when it is alternately turned around the pulley and straightened again, and with high longitudinal flexibility this considerably prolongs the life of the belt and allows the use of relatively small diameters of the pulleys. Completely or substantially similar dynamic properties in the pressure and tension zone of the belt material also make the belt itself more flexible compared to said known belts made of a variety of 65063 different materials, in particular fibrous rubber, textile layer and soft rubber without fibers, has different bending stiffness values. The omission of the textile makes the belt easier to manufacture and eliminates the need for post-grinding of the sloping side surfaces of the belt, which is necessary in the prior art if the blades cutting the belts from the vulcanized sleeve become inverted by relatively hard textile layers.

It is also important for the running characteristics of the belt to avoid variations in the cross-sectional height of the belt caused by the overlap of the textile layers, resulting in more vibration-free transmission and less tendency to belt noise (whistling sound).

From a manufacturing point of view, it is advantageous that the pressures in the traction zone are the same rubber compound. However, it is obvious that the advantages of the invention can also be achieved even if two substances are used, the compositions of which are slightly different, as long as their dynamic properties meet the set requirements and are otherwise substantially similar.

The invention will now be described in more detail with reference to a schematic drawing in which: Figure 1 shows a cross-sectional view of a known V-belt; Fig. 2 shows a corresponding cross-sectional view of another known V-belt; and Figure 3 shows a cross-sectional view of an embodiment of a V-belt according to the invention.

The V-belt shown in Fig. 1 has an outermost cover layer 1 of impregnated textile fabric, and inside this layer is an incomparably thin rubber layer 2 containing short fibers whose main orientation is perpendicular to the longitudinal direction of the belt and parallel to the cover layer 1. Layer 2 forms the traction zone of the V-belt. Inside the layer 2 there is a layer 3 of soft rubber, which must ensure an adhesion between the layer 2 and a substantially or completely uniform layer consisting of force-transmitting cord young H completely embedded in the layer 3. Inside the layer 3 follows a relatively high layer 5 of rubber. mixed with 66063 fibers analogously to layer 2, and layer 5 is covered on the inside of the belt by a layer 6 of a rubber-impregnated textile fabric.

The belt according to Fig. 2 differs from that according to Fig. 1 only in that the fibrous rubber layer 2 is omitted and that the tensile zone of the cross-section of the belt is instead formed by a larger number of layers 1 of rubber-impregnated textile fabric which are superimposed.

Both of the described types of belts are generally made by turning successive layers of material on the mandrel, cut to a suitable width, to form a sleeve which is vulcanized, and then the belts are cut from the sleeve. Alternatively, the various belts can also be cut from a non-vulcanized sleeve and then vulcanized individually in a corresponding form.

In Fig. 3, the number 11 indicates the tensile zone of the belt cross-section, the number 12 the embedded cord young and 13 the cross-sectional pressure zone. In this belt, both layers 11 and 13 consist of the same rubber compound with embedded fibers, the majority of which are oriented as shown, i. perpendicular to the longitudinal direction of the belt and parallel to the upper and lower edges of the cross-section. Thus, there is no inner or outer cover layer formed by the textile material, nor a special soft rubber layer around the cord young 12.

In the manufacture of the belt according to Figure 3, the procedure can be as follows:

In the calender, a rubber mixture containing evenly distributed and randomly oriented fibers is rolled into thin webs, whereby most of the fibers of the rolled web become oriented in the Vals dry direction. Since the degree of orientation and thus the longitudinal stiffness of the rolled material increases as the track thickness decreases, the calender must be adjusted to a relatively narrow slot in the transverse direction of the belt to achieve maximum rigidity Pieces of a length corresponding to the length of the mandrel mentioned below and of a width corresponding to the the circumference of the belt zone.

6 6063

A plate is wound in the inner part of the mandrel, which forms a pressure zone 13 in the finished belts and the longitudinal edges of which are preferably ground in advance. Outside this, a layer of cord twine is wound, e.g. in the form of a single screw-wound string in which the bends are tightly close together, and outside the cord twine is wound a plate which forms a tension zone 11 in the finished belt.

To ensure good interdependence between the two rubber layers and the cord cords, the cords can be pre-impregnated in a known manner, e.g. with resorcinol latex (RFL) if the cord cords consist of textile yarns. In addition to cord impregnation, the opposite surfaces of the two rubber sheets can be coated by brushing them with a rubber solution or solvent, e.g. toluene, which softens the surfaces and further cleans them.

The sleeve thus formed is vulcanized and then various V-belts are cut therefrom in the usual manner, e.g. by means of rotating blades, the oblique position of which corresponds to the inclination of the oblique side surfaces of the belt. Since in the described procedure the fibers of the rubber mixture are oriented substantially parallel to the axis of the mandrel and the sleeve, the fibers in the finished belts become oriented substantially perpendicular to the longitudinal direction of the belt and parallel to the outer and inner side of the belt.

For the sake of completeness, it should be mentioned that, especially in the case of large belts, each belt can be manufactured separately by pre-cutting the pressure zone and the tension zone with the finished dimensions and method otherwise as described above.

The rubber composition of layers 11 and 13 may be based on various elastomers such as SBR, natural rubber, chloroprene, nitrile rubber, silicone rubber, EPDM or mixtures of such elastomers. The fibers of the rubber mixture can be, for example, polyester, glass, aromatic polyamide, sparkler or cotton. They can be produced in a known manner by carding or simplifying textile waste to a relatively high degree of fineness, so that the finished fiber-blend mixture does not have substantially larger fiber deposits. The normal length of the fibers is about 2-20 mm and in this context it is clear that the degree of orientation achieved by the fibers in said calendering increases with decreasing length of the fibers. Prior to mixing, the synthetic fibers of the verse can be impregnated with known substances which improve their adhesion to the rubber.

--- - Γ 6 6 5063

The cord 12 can be formed in a known manner from natural fibers, in particular cotton fibers, man-made fibers, e.g. fibers or strands of polyester or aromatic polyamide, glass or steel fibers.

The following are two examples of rubber compounds that can be used in the belts of the invention.

Example 1

Parts by weight

Smoke rubber plate 24 SBR 1500 70

Reclaimed rubber 10

Antioxidant 1

Cotton or polyester fibers 20 SRF-black 100

Procedure 12

Cumar resin 5

Zinc oxide 5

Mercaptobenzothiazole 2

Tiuram monosulfide 1

Retarder 0.2

Sulfur 2.2 252.4

Example 2

Parts by weight

Chloroprene 100 OCD octyldiphenylamine 1.5 p-phenylenediamine 0.75

Mercaptobenzothiazole disulfide 0.75

Magnesium oxide 4

Sodium acetate 1

Fine thermal black 20

Conductive black 20 Pine tar 2

Flexol 4G0 (plasticizer) 5

Cotton or polyester fibers 22

Stearic acid 1

Zinc oxide 2,180.00 66063 The test pieces made of these two fiber rubber mixtures gave the following E’ and E ”values when measured in said Rheovibron device, whereby the force acting on the test pieces was pulsating at 35 Hz.

Example 1

E ’parallel to the fiber direction 7.5 x 107 Pascal temp. 50 ° C

4.0 x 107 Pascal temp. 120 ° C

7 o

E ”parallel to the fiber direction 1.6 x 1 <J Pascal temp. 50 C

0.6 x 107 Pascal temp. 120 ° C 7 ° C

E1 perpendicular to the fiber direction 1.9 x 10 Pascal temp. 50 C

1.3 x 107 Pascal temp. 120 ° C

E "perpendicular to the fiber direction 1.9 x 10® Pascal temperature 50 ° C

1.5 x 106 Pascal temp. 120 ° C

Example 2

E 'parallel to the fiber direction 14 x 107 Pascal temp. 50 ° C

6.0 x 107 Pascal temp. 120 ° C

7 o

E "parallel to the fiber direction 2.4 x 10 Pascal at 50 ° C

0.7 x 107 Pascal temp. 120 ° C

E * perpendicular to the fiber direction 2.9 x 107 Pascal temp. 50 ° C

2.0 x 107 Pascal temp. 120 ° C

E "perpendicular to the fiber direction 3.4 x 10® Pascal temperature 50 ° C

1.6 x 10® Pascal temp. 120 ° C

The belts made of the two rubber compounds as described underwent durability measurements and flexibility measurements and were compared with the measurements of the corresponding belts made by a known method with textile fabric inserts and / or coatings. It was found that the service life of the belts according to the invention in measurements which mimic normal belt loading, e.g. as described in B.S. AU150 (July 1973) or DIN 7753 Part 4 (Entwurf December 1976), was about 3.1 times the service life of a standard belt. Flexibility measurements, in which the belts pass at an extreme speed over two extremely small pulleys without transferring power, but with an unusually high belt tension, which is obtained by loading the pulleys apart, showed the belts of the invention a lifetime of about 1.6 times

Claims (4)

66063 Life of 8 standard belts. It was also found that the belts of the invention were practically not stretched, so that in practice it is possible to dispense with the post-tensioning or adjustment of the pulley gap, which must otherwise be done after a certain running-in time. A V-belt consisting solely of a traction zone (11), a pressure zone (13) and power-transmitting cord young placed between the traction zone and the pressure zone, and wherein the traction zone and the pressure zone consist of rubber alloys in which fibers are embedded, and wherein , characterized in that most of the fibers embedded in the rubber compounds are oriented in a manner known per se perpendicular to the longitudinal direction of the belt and parallel to the upper and lower edges of the cross-section of the belt; that the ratio between the energy storage module E 'of the rubber compound measured parallel to the main fiber direction and the energy storage module E' measured perpendicular to the main fiber direction at the same temperature in the temperature range 50 to 120 ° C; and that the ratio between the energy storage module E 'of the mixture and its loss modulus E ", both measured parallel to the main fiber direction and at the same temperature in the temperature range of 50 to 120 ° C, is greater than 4.5. V-belt according to Claim 1, characterized in that the energy storage module E 'of the rubber compound in the temperature range 50 to 120 ° C and at a measuring frequency of 35 Hz is at least 4 x 10 Pascal measured parallel to the main fiber direction and at most 3 x 10 Pascal measured perpendicular to the main fiber direction. V-belt according to Claim 1 or 2, characterized in that the loss modulus E "of the rubber compound, measured perpendicular to the main fiber direction at a measuring frequency of 35 Hz, is at most 4 x 10 ° Pascals in the temperature range 50 to 120 ° C. V-belt according to Claims 1 to 3, characterized in that the loss modulus E "of the rubber compound, measured in parallel with the main fiber direction at a measuring frequency of 35 Hz, is at most 2.5 x 10 6 Pascals in the temperature range 50 to 120 ° C.