JP2010230147A - High-load transmission belt and block for high-load transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt reducing an abrasion amount on a contact face with a pulley to elongate a service life, while maintaining a high friction coefficient of a block and mechanical strength such as rigidity. <P>SOLUTION: A high-load transmission belt 1 is constituted of a plurality of blocks 2 disposed at a predetermined pitch along a longitudinal direction of a center belt 3. The block 2 is formed of a resin composition prepared by mixing a fiber reinforced material comprising carbon fiber, aramid fiber, or the like, and a friction reducing material comprising graphite or the like, into a thermoplastic resin. The 30-89 mass% of thermoplastic resin, 10-60 mass% of fiber reinforced material, and 1-50 mass% of friction reducing material are mixed into a total quantity of resin composition. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high-load transmission belt and a block for a high-load transmission belt in which blocks are fixed at a predetermined pitch along the longitudinal direction of a center belt.

  The belt used in the belt type continuously variable transmission is used by being wound around a transmission pulley that changes the effective diameter of the pulley by adjusting the V groove width of the pulley and adjusts the transmission gear ratio. Because the side pressure from the belt increases, the belt must withstand a large side pressure. In addition to continuously variable speed applications, it is necessary to use a belt that can withstand a high load, especially for high-load transmission applications where the life of conventional rubber belts is too short.

  Among such belts, there is a tensile transmission type high-load transmission belt in which a block is fixed to the center belt to increase the strength in the belt width direction. A block made of an elastomer that is relatively harder than the elastomer used for the center belt is fixed to the center belt embedded in the elastomer using a fixing material such as a bolt or a rivet.

  As the block, a metal core material such as aluminum whose surface is coated with a resin has been proposed (Patent Document 1). However, due to diversification of needs, the load is somewhat low, but the rotation speed is high and the pulley diameter is small. A block having a metal core material inevitably increases the weight of the core material, and when the belt is run at a high speed, there is a problem that the centrifugal tension increases and the belt is damaged early.

  Therefore, a belt using a block made only of a resin material without using a core material has been proposed. Even if the load is low, sufficient mechanical strength is required for the block, and in Patent Document 2, PAN-based carbon fiber and whisker are blended with thermoplastic resin such as 4,6-nylon. It is described that it can resist lateral pressure even if the core material is not embedded, and because it is lightweight, it has a low centrifugal tension during belt running and can prevent damage to the belt.

  Furthermore, Patent Document 3 describes a high-load transmission belt that uses 9, T-nylon as a polyamide resin to reduce the weight without using a core material and is further superior in strength. . Patent Documents 2 and 3 also describe blending various whiskers.

  In addition to mechanical strength, the performance required for such a block may be excellent in wear resistance. Although it is conceivable to reduce the wear of the block by sliding it with a material having a low friction coefficient, this belt is originally a V-belt and transmits power by friction between the block and the pulley. When the slip ratio is too high due to a low value, the transmission efficiency of the belt itself decreases, which leads to a fundamental problem.

  Patent Document 4 discloses a belt using a block in which carbon fiber and a friction reducing material are blended with a thermoplastic resin. By using calcium carbonate whisker or calcium phosphate whisker as the friction reducing material, the mechanical strength of the block is disclosed. A technique for reducing wear due to friction of a block without reducing the friction is disclosed.

  Similarly, Patent Document 5 discloses a belt using a block in which carbon fiber and a friction reducing material are blended with a thermoplastic resin. In Patent Document 5, graphite is used as a friction reducing material, but this also results in less wear of the block in the wear test.

  Patent Document 6 discloses a self-lubricating composition in which a low-density polyethylene and an aramid powder are blended with a polyoxyalkylene resin, and describes that friction characteristics and wear resistance are improved.

Japanese Patent Laid-Open No. 10-73149 JP 2001-31453 A JP 2002-195351 A JP 2008-180344 A (calcium carbonate, calcium phosphate) JP 2008-208996 A (Graphite) JP 2005-521554 A

  By using a resin reinforced with fibers or whiskers as described above, the wear resistance and rigidity of the block can be increased. However, if the belt is run for a long period of time, block wear will occur, and there will be a problem that the transmission ratio will be reduced due to the influence of the gear ratio and slip, without reducing the mechanical strength and friction coefficient. Further improvement in wear resistance is desired.

  Accordingly, an object of the present invention is to provide a belt capable of reducing the amount of wear of the block while maintaining a moderate coefficient of friction on the contact surface of the block with the pulley and without reducing mechanical strength such as rigidity. .

  In order to achieve the above object, according to claim 1 of the present invention, a center belt in which a core is embedded in an elastomer, and a plurality of blocks provided at a predetermined pitch along the longitudinal direction of the center belt. In the high load transmission belt, the block is made of a resin composition in which at least a fiber reinforcing material and a friction reducing material are blended with a thermoplastic resin, and 30 to 89% by mass of the thermoplastic resin with respect to the total amount of the resin composition. A high-load power transmission belt comprising 10 to 50% by mass of a reinforcing material and 1 to 30% by mass of a friction reducing material, wherein the friction reducing material is an aramid powder.

  In Claim 2, it is set as the high load transmission belt of Claim 1 whose average particle diameter d50 of aramid powder is 1-100 micrometers.

  In the high load transmission belt block used for the high load transmission belt comprising a plurality of blocks provided at a predetermined pitch along the longitudinal direction of the center belt, the thermoplastic resin includes at least a fiber reinforcing material and a friction reducing material. The thermoplastic resin is 30 to 89% by mass, the fiber reinforcement is 10 to 50% by mass, and the friction reducing material is 1 to 30% by mass with respect to the total amount of the resin composition. The friction reducing material is an aramid powder.

  In Claim 4, it is set as the block for high load transmission belts in any one of Claim 3 whose average particle diameter d50 of aramid powder is 1-100 micrometers.

  In claim 1, since the block made of thermoplastic resin is blended with a friction reducing material made of fiber reinforcing material and aramid powder, it is lightweight and suitable for use at high revolutions and has sufficient block strength. The amount of wear of the block can be greatly reduced at the contact surface of the block with the pulley during belt running.

  In the second aspect, the average particle diameter d50 of the aramid powder used as the friction reducing material is 1 to 100 μm, the dispersion in the resin is good, and the effect of wear resistance can be sufficiently exhibited.

  In the third aspect, the block made of thermoplastic resin and the friction reducing material made of aramid powder are blended in the block made of the thermoplastic resin as in the first aspect, so that the block is light and suitable for use at high rotation. Further, the wear amount of the block can be greatly reduced on the contact surface of the block with the pulley during belt running.

  In the fourth aspect, the average particle diameter d50 of the aramid powder used as the friction reducing material is set to 1 to 100 μm as in the second aspect, the dispersion in the resin is good, and the effect of wear resistance can be sufficiently exhibited. .

  Hereinafter, the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a schematic perspective view showing an example of a high-load transmission belt 1 according to the present invention, and FIG. 2 is a side view. The high-load transmission belt 1 of the present invention is fixed to two center belts 3a and 3b having the same width formed by embedding a core wire 5 in a spiral shape in an elastomer 4, and the center belts 3a and 3b. A plurality of blocks 2. Both side surfaces 2a and 2b of the block 2 are inclined surfaces that engage with the V-grooves of the pulleys, and receive the power from the driven pulleys and are locked and fixed by the center belts 3a and 3b. The power of the driving pulley is transmitted to the driven pulley.

  As shown in FIGS. 1 and 2, the block 2 includes an upper beam 11 and a lower beam 12, and pillars 13 that connect the central portions of the upper and lower beams 11 and 12, and both side surfaces 2 a and 2 b of the block 2. Are formed with grooves 14 and 15 into which the pair of center belts 3a and 3b are fitted. Further, the groove upper surface 16 and the groove lower surface 17 in the groove 15 are related to the ridge portions 20 and 21 engaged with the ridge portion 18 provided on the upper surface of the center belt 3a, 3b and the ridge portion 19 provided on the lower surface. It comes to match.

  Further, in the present invention, the material used as the block 2 is composed of a resin composition in which at least a fiber reinforcing material and a friction reducing material are blended with a thermoplastic resin, and the thermoplastic resin is 30 to 89% by mass with respect to the total amount of the resin composition. The fiber reinforcing material is blended at a rate of 10 to 40% by mass, and the friction reducing material is blended at a rate of 1 to 20% by mass.

  Examples of the thermoplastic resin include polyethylene, polypropylene, polyacetal, 4,6-nylon, 9, T-nylon, and the like. Among these, it is preferable to use 4,6-nylon or 9, T-nylon. 4,6-Nylon and 9, T-Nylon are crystalline resins and are excellent in mechanical strength such as rigidity and abrasion resistance among thermoplastic resins, and these characteristics are further improved by adding a fiber reinforcing material. Is. In addition, since injection molding is possible, there is an advantage that it is easier to mold the block. Furthermore, since belts using blocks made of 4,6-nylon or 9, T-nylon are less likely to wear the pulley when running, there is less of a problem of unstable running due to wear of the pulley. .

  9, T-Nylon is a polyamide resin having an aromatic ring and a long-chain diamine, which is produced by polycondensation of nonanediamine and terephthalic acid, and has an aromatic ring and a higher aliphatic chain. It has sex. Further, since it is a homopolymer and has a high degree of crystallinity, it is excellent in wear resistance, impact resistance and fatigue resistance as in the case of 4,6-nylon compared to polyamide having a low degree of crystallinity. Therefore, by using this material, it is possible to obtain a block having excellent physical properties such as wear resistance, impact resistance, fatigue resistance, and bending rigidity during heating, and having few water absorption problems. As an example of the product of 9, T-nylon, “Genesta” of Kuraray Co., Ltd. can be mentioned.

  Moreover, the following are mentioned as a specific example of other resin. Polyacetal: Polyplastic Co., Ltd. “Duracon”, 4,6-Nylon: Kuraray Co., Ltd. “Stanyl”, 6,6-Nylon: Asahi Kasei Chemicals Corporation “Leona”, 6-Nylon: Ube Industries, Ltd. “UBE Nylon”.

  Although the rigidity and wear resistance of the block can be improved by blending a fiber reinforcing material, the fiber reinforcing material used in the present invention is a short fiber made of carbon fiber, aramid fiber, glass fiber, polyester fiber, etc. Can be mentioned. Among these fibers, it is most preferable to use carbon fibers, and more preferable to use PAN-based carbon fibers from the viewpoints of increasing the rigidity of the block and improving the wear resistance.

  The PAN-based carbon fiber is a fiber having a high elastic modulus and a high reinforcing effect in the first place. Among them, by using a fiber having a particularly high elastic modulus of 280 to 700 GPa, the PAN-based carbon fiber is used as a block of a high load transmission belt as in the present invention. It is possible to provide a material that can withstand sufficient use. If the elastic modulus is less than 280 GPa, the side pressure resistance of the block can be obtained to some extent, but the wear resistance is insufficient, and if it exceeds 700 GPa, even if the elastic modulus is high, the side pressure resistance and the wear resistance are not improved. Since it is not seen so much and becomes expensive, it is not preferable.

  The length of the fiber reinforcing material is usually about 0.1 to 10 mm. The blending amount of the fiber reinforcement is 10 to 60% by mass, and if it is less than 10% by mass, a sufficient reinforcing effect cannot be obtained, and if it exceeds 60% by mass, block injection molding becomes difficult, which is not preferable. .

  As the friction reducing material, aramid powder is used in the present invention. The aramid powder is an aramid fiber whose average particle diameter d50 is refined to 100 μm or less, and by blending it in a resin, the friction coefficient can be reduced and the wear resistance can be improved. As the types of aramid fibers, there are meta-based and para-based aramids, both of which can be used. However, it is preferable to use para-based aramid. Para-aramid fibers can be said to be a preferred form because they have less deterioration in mechanical strength when blended than meta-aramid fibers, and are highly effective in improving wear resistance.

  It is preferable to use an aramid powder having an average particle diameter d50 in the range of 1 to 100 μm. If a particle having a particle size exceeding 100 μm is used, the dispersion state in the resin will deteriorate, the strength of the entire block will vary, and it will be difficult to obtain uniform performance for improved wear resistance. It is not preferable.

  Moreover, it is preferable to mix | blend the compounding quantity within the range of 1-30 mass%. If the amount is less than 1% by mass, the effect of improving the wear resistance cannot be obtained. Moreover, since the tendency to fall also in strength appears, it is not preferable.

  As the elastomer 4 for the center belts 3a and 3b, a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, or a rubber or polyurethane rubber obtained by appropriately blending them is used. Can be mentioned. As the core 5, a rope selected from polyester fiber, polyamide fiber, aramid fiber, glass fiber, steel wire and the like is used. Moreover, the core wire 5 can also use the woven fabric, knitted fabric, metal thin plate, etc. which consist of said fiber other than what embedded the rope in spiral shape.

  Next, a test piece made of a resin molded product having the same composition as the block containing a predetermined amount of the aramid powder used in the high load transmission belt of the present invention, and a test piece made of a resin molded body having a composition deviating from the present invention The friction coefficient and wear amount of the resin were compared.

Example 1
As Example 1, 65% by mass of polyamide 46 and 30% by mass of carbon fiber as a fiber reinforcing material were used, and Technora (manufactured by Teijin Ltd.), which is a para-aramid fiber, was used as a wear reducing material, with an average particle size d50 of 10 μm. 5% by mass of the above powder was blended to prepare a resin molded body serving as a test sample.

  Using this resin molding, the flexural modulus, friction coefficient, and wear amount were measured by a thrust wear test. The measurement conditions were a load of 1.5 MPa and a sliding speed of 0.5 m / s. The amount of wear was measured as the amount of decrease in the thickness of the molded resin before and after the thrust friction wear test. The results are shown in Table 1.

(Example 2)
In Example 2, a resin molded body serving as a test sample was produced in the same manner as in Example 1 except that a powder having an average particle diameter d50 of 10 μm was used as the wear reducing material.

  Using this resin molding, the flexural modulus, friction coefficient, and wear amount were measured by a thrust wear test. The measurement conditions were a load of 1.5 MPa and a sliding speed of 0.5 m / s. The amount of wear was measured as the amount of decrease in the thickness of the molded resin before and after the thrust friction wear test. The results are shown in Table 1.

Example 3
In Example 3, a resin molded body serving as a test sample was obtained in the same manner as in Example 1 except that a powder having an average particle diameter d50 of 50 μm was used as a wear-reducing material with Twaron (manufactured by Teijin Ltd.) which is a para-aramid fiber. Produced.

  Using this resin molding, the flexural modulus, friction coefficient, and wear amount were measured by a thrust wear test. The measurement conditions were a load of 1.5 MPa and a sliding speed of 0.5 m / s. The amount of wear was measured as the amount of decrease in the thickness of the molded resin before and after the thrust friction wear test. The results are shown in Table 1.

Example 4
In Example 4, 40% by mass of polyamide 46 and 30% by mass of carbon fiber as a fiber reinforcing material were blended, and Technora (manufactured by Teijin Ltd.), which is a para-aramid fiber, was used as a wear reducing material, with an average particle size d50 of 50 μm. 30% by mass of the above powder was blended to prepare a resin molded body serving as a test sample.

  Using this resin molding, the flexural modulus, friction coefficient, and wear amount were measured by a thrust wear test. The measurement conditions were a load of 1.5 MPa and a sliding speed of 0.5 m / s. The amount of wear was measured as the amount of decrease in the thickness of the molded resin before and after the thrust friction wear test. The results are shown in Table 1.

(Comparative Example 1)
As Comparative Example 1, 70% by mass of polyamide 46 and 30% by mass of carbon fiber as a fiber reinforcing material were blended to prepare a resin molded body serving as a test sample.

  Using this resin molding, the flexural modulus, friction coefficient, and wear amount were measured by a thrust wear test. The measurement conditions were a load of 1.5 MPa and a sliding speed of 0.5 m / s. The amount of wear was measured as the amount of decrease in the thickness of the molded resin before and after the thrust friction wear test. The results are shown in Table 1.

(Comparative Example 2)
As Comparative Example 2, 35% by mass of polyamide 46 and 30% by mass of carbon fiber as a fiber reinforcing material were blended, and Technora (manufactured by Teijin Ltd.), which is a para-aramid fiber, was used as a wear reducing material, with an average particle size d50 of 50 μm. An attempt was made to prepare a resin molded body as a test sample by blending 35% by mass of this powder, but melt kneading could not be performed.

  From the results of Table 1, in the test samples of Examples 1 to 4 in which aramid powder was blended within a predetermined range as a wear reducing material, the flexural modulus was a numerical value substantially equivalent to that of Comparative Example 1 in which no aramid powder was blended. The friction coefficient was also the same, but the amount of wear was reduced to about half, and the effect of improving the wear resistance by adding the aramid powder was confirmed. Further, in Comparative Example 2 in which the blending amount of the aramid powder was 35% by mass, it was found that the molding itself could not be performed if the blending amount of the aramid powder was excessive.

  Belts that can prevent cracks by suppressing multiple directions of bending of blocks attached to the belt, such as cars, motorcycles, continuously variable transmissions for agricultural machinery, etc., belts that change the effective diameter of pulleys and transmit large torque Can be applied as

It is a perspective schematic diagram showing an example of the high load transmission belt concerning the present invention. It is a side view of the high load power transmission belt concerning the present invention.

DESCRIPTION OF SYMBOLS 1 High load transmission belt 2 Block 3a Center belt 3b Center belt 4 Elastomer 5 Core body 6 Upper surface 7 Lower surface 11 Upper beam part 12 Lower beam part 13 Center pillar 14 Fitting groove 15 Fitting groove 18 Convex part 19 Convex part 20 Groove part 21 Groove part

Claims (4)

  In a high load transmission belt comprising a center belt in which a core body is embedded in an elastomer and a plurality of blocks provided at a predetermined pitch along the longitudinal direction of the center belt, the block includes at least a fiber reinforcing material and a thermoplastic resin. It consists of a resin composition containing a friction reducing material, 30 to 89% by mass of a thermoplastic resin, 10 to 50% by mass of a fiber reinforcing material, and 1 to 30% by mass of a friction reducing material with respect to the total amount of the resin composition. A high-load power transmission belt, characterized in that the friction reducing material is aramid powder.   The high load transmission belt according to claim 1, wherein the average particle diameter d50 of the aramid powder is 1 to 100 µm.   A resin composition in which at least a fiber reinforcing material and a friction reducing material are blended in a thermoplastic resin in a high load transmission belt block used for a high load transmission belt comprising a plurality of blocks provided at a predetermined pitch along the longitudinal direction of the center belt From a resin composition comprising 30 to 89% by mass of a thermoplastic resin, 10 to 50% by mass of a fiber reinforcing material, and 1 to 30% by mass of a friction reducing material with respect to the total amount of the resin composition. A high load transmission belt block characterized in that the friction reducing material is aramid powder.   The high load transmission belt block according to claim 3, wherein the average particle diameter d50 of the aramid powder is 1 to 100 μm.

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