JP2010060068A - Belt system, toothed belt and pulley for the belt system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt system etc. suppressing noise production even in a severe use environment requiring to achieve large engagement accuracy and endure large load. <P>SOLUTION: The belt system 30 includes a toothed belt and a pulley 40. When a tooth 20 of the toothed belt is engaged with a pulley groove 42, a first clearance G<SB>1</SB>is provided between the tooth 20 and an inflection point 42T of the pulley groove 42. A second clearance G<SB>2</SB>is provided between the top 20P of the tooth 20 in the engagement position and a central point 42P of a pulley groove bottom face 42B. Thus, when the toothed belt is running so that the tool 20 is engaged with the pulley groove 42, only a compression region 20C is brought into contact with the pulley groove 42 on a tooth flank 20S, to suppress noise production. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a belt system and the like, and more particularly, to a belt system including a toothed belt and a pulley.

  Conventionally, a belt system including an endless toothed belt and a pulley has been widely used for power transmission (see, for example, Patent Document 1). In such a belt system, the toothed belt is wound between a driving pulley and a driven pulley.

Pulley grooves are formed along the circumferential direction on the outer peripheral surfaces of these pulleys, and belt tooth portions that engage with the pulley grooves are formed on the toothed belt. As the drive pulley rotates, the belt teeth sequentially engage with the pulley groove, whereby the rotational driving force is transmitted to the toothed belt.
Japanese Patent No. 3601987

  Due to an increase in the size of a machine in which the belt system is used, the load on the toothed belt increases, and high meshing accuracy between the tooth portion and the pulley tends to be required. For this reason, the problem that the noise generated from the running toothed belt increases may arise. Especially when high installation tension is required due to the elimination of backlash to improve meshing accuracy, or when the toothed belt changes due to long-term use, the noise can be further increased. There is sex.

  Accordingly, an object of the present invention is to realize a belt system or the like that can suppress the generation of noise even in a severe use environment that needs to withstand high meshing accuracy and a large load.

  The belt system according to the present invention is a belt system including a toothed belt having a round tooth portion and a pulley provided with a pulley groove with which the tooth portion is engaged. In the belt system, the contour shape of the tooth part and the pulley groove is such that when the tooth part is engaged with the pulley groove, the pulley groove is located on the apex side of the tooth part from the center of the tooth height on the tooth surface of the tooth part. Compress only the region, provide a first gap between the tooth portion at the inflection point of the contour shape provided near the end of the pulley tooth tip surface in the pulley groove, the apex of the tooth portion and the pulley groove bottom, The second gap is adjusted to provide a second gap.

  The compression region preferably includes a region in the tooth surface where the distance from the apex of the tooth portion is 1/4 of the tooth height and a plane parallel to the tooth bottom surface of the toothed belt intersects. The pulley groove preferably compresses the compression region in the direction of 45 ° with respect to the bottom surface of the toothed belt. Moreover, it is preferable that the compression ratio of the tooth part in the direction by the pulley groove is 0.5% or more and 3.0% or less based on the tooth height. In this case, the compression rate is 0.8%, for example.

  The size of the first gap is preferably 0.5% or more and 3.0% or less of the belt pitch. In this case, the size of the first gap is, for example, 1.0% of the belt pitch.

  In the belt system, the curvature of the pulley tooth side region, which is the region closer to the end of the pulley tooth tip surface than the inflection point in the pulley groove, is the pulley groove bottom side, which is the region on the pulley groove bottom side from the inflection point. It is preferably larger than the curvature of the region. In addition, when the toothed belt is traveling so that the tooth portion engages with the pulley groove, it is preferable that only the compression region contacts the pulley groove on the tooth surface.

  The toothed belt of the present invention is used in the above-described belt system. The hardness of the rubber layer material forming the tooth portion is preferably A92 (JIS K-6253) or higher. The toothed belt preferably has an S glass core. The tooth portion is preferably formed of a rubber layer material containing HNBR.

  The pulley of the present invention is characterized by being used in the belt system described above.

  ADVANTAGE OF THE INVENTION According to this invention, the belt system etc. which can suppress generation | occurrence | production of noise can be implement | achieved also in the severe use environment which needs to endure high meshing precision and a big load.

  Hereinafter, the belt system of the present embodiment will be described with reference to the drawings. FIG. 1 is a perspective view showing a part of a toothed belt according to this embodiment in a cutaway manner.

  The belt system of this embodiment includes a toothed belt 10. The toothed belt 10 includes a tooth rubber layer 12 and a back rubber layer 14. The surface of the tooth rubber layer 12 is covered with a canvas 16. A core wire 22 is embedded between the tooth rubber layer 12 and the back rubber layer 14 along the longitudinal direction of the toothed belt 10. The toothed belt 10 includes a round tooth-shaped tooth portion 20 formed by the tooth rubber layer 12. A tooth bottom surface 24 is formed between adjacent tooth portions 20.

  FIG. 2 is a cross-sectional view showing a state where the tooth portion of the toothed belt is engaged with the pulley groove in the belt system of the present embodiment. FIG. 3 is a sectional view showing a belt system of a comparative example corresponding to FIG. In these drawings, for convenience of explanation, only a part of the toothed belt 10, that is, only a part of the tooth surface 20 </ b> S and the tooth bottom surface 24 which are the surfaces of the tooth part 20 are shown.

  The belt system 30 includes a pulley 40. The pulley 40 is provided with a pulley groove 42 with which the tooth portion 20 is engaged. Hereinafter, the state where the tooth portion 20 is engaged with the pulley groove 42 means that the apex 20P of the tooth portion 20 is directly above the center point 42P of the pulley groove bottom surface 42B (pulley groove bottom) as shown in FIG. There is a state in which a straight line D connecting the vertex 20P and the center point 42P overlaps the diameter of a pitch circle (not shown) of the pulley 40. The apex 20P of the tooth portion 20 is the center point of the tooth surface 20S.

Tooth surface 20S, after teeth 20 is in the position shown by the curve L ₁ is prior to engaging the pulley groove 42, engaged with the pulley groove 42 at the engagement position illustrated by solid lines, It moves to the position shown by the curve L _2. When the toothed belt 10 travels on the pulley 40, the tooth portion 20 repeats such movement.

  In the present embodiment, the contour shapes of the tooth portion 20 and the pulley groove 42 are adjusted in order to suppress noise generated when the toothed belt 10 travels. Hereinafter, the outline shapes of the tooth portion 20 and the pulley groove 42 will be described.

  When the tooth portion 20 engages with the pulley groove 42, the compression region 20 </ b> C in the tooth surface 20 </ b> S contacts the pulley groove 42. For this reason, only the compression region 20 </ b> C is compressed by the pulley groove 42 on the tooth surface 20 </ b> S. The compression region 20C is provided closer to the vertex 20P than the center point C of the tooth height 20H, which is the distance from the extended surface 24S of the tooth bottom surface 24 to the vertex 20P. More specifically, the compressed region 20C includes a region where a distance from the apex 20P is ¼ of the tooth height 20H and a plane 24A parallel to the tooth bottom surface 24 intersects the tooth surface 20S.

  The pulley groove 42 compresses the compression region 20 </ b> C in a direction of 45 ° with respect to the tooth bottom surface 24 as indicated by an arrow E in a state where the tooth portion 20 is engaged with the pulley 40. The compression ratio in the direction of the compression region 20C by the pulley groove 42 is about 0.5% or more and 3.0% or less based on the tooth height 20H.

  This is because when the compression rate is smaller than 0.5%, the tooth portion 20 is not firmly held by the pulley groove 42, and the vibration of the tooth portion 20 causes a large noise, while the compression rate is 3.0%. This is because jumping (tooth skipping) occurs and the durability of the toothed belt 10 may be reduced. In the present embodiment, the shapes of the tooth portion 20 and the pulley groove 42 are adjusted so that the compression rate is 0.8%.

  The curvature of the surface of the pulley groove 42 differs from the inflection point 42T. That is, in the pulley groove 42, the region of the pulley tooth tip surface 40S side (pulley tooth side region) from the inflection point 42T has a larger curvature than the region of the pulley groove bottom surface 42B side (pulley groove bottom side region). Since FIG. 2 is a cross-sectional view, an inflection point 42T is shown. However, in the pulley groove 42 of the actual thick pulley 40, it passes through the inflection point 42T and extends perpendicularly to the paper surface of FIG. The curvature of the pulley groove 42 differs from the straight line.

Between the teeth 20 and the inflection point 42T in the engaged position, the first gap G ₁ is provided. The size of the first gap G ₁ is a degree of 0.5% to 3.0% or less of a belt pitch of the toothed belt 10, shown exaggerated in FIG. The belt pitch is a distance between centers of adjacent tooth portions 20 (belt teeth) of the toothed belt 10.

The first gap G ₁ is, if less than 0.5 percent of the belt pitch, there is a possibility that noise is increased by contact with the tooth portion 20 and the pulley 40. Further, when the first gap G ₁ is greater than 3.0% of the belt pitch, since the pulley tooth crest 40S between adjacent pulley groove 42 is narrowed, the root surface 24 is the pulley tooth tip of the toothed belt 10 The force per unit area received when contacting the surface 40S increases, and the durability of the toothed belt 10 can be reduced. From the above, in the present embodiment, the size of the first gap G ₁ is 1.0% of the belt pitch.

As described above, the pulley tooth crest 40S vicinity of the pulley groove 42, for which gently curved so as to widen the opening of the pulley groove 42, further first gap G ₁ is provided, the tooth surface 20S A region closer to the tooth bottom surface 24 than the compression region 20 </ b> C is prevented from contacting the pulley groove 42.

On the other hand, the pulley groove bottom surface 42B is recessed in the vicinity of the center point 42P from its periphery. The shape of such a pulley groove 42, and the vertex 20P of teeth 20 in the engaged position, between the center point 42P of the pulley groove bottom surface 42B, a second gap G ₂ is provided. For this reason, it is prevented that the vertex 20P of the tooth | gear part 20 which moves through an engagement position contacts the pulley groove bottom face 42B.

  As described above, in the present embodiment, when the toothed belt 10 is traveling so that the tooth portion 20 is engaged with the pulley groove 42, only the compression region 20 </ b> C is formed in the pulley groove 42 on the tooth surface 20 </ b> S of the tooth portion 20. Contact. For this reason, since the compression region 20C is held by the pulley groove 42, a correct meshing state is maintained, unnecessary contact between the tooth portion 20 and the pulley groove 42 is prevented, and generation of a large noise is prevented. The

  On the other hand, the belt system 70 (see FIG. 3) of the comparative example includes a toothed belt and a pulley 80 in which only a part of the tooth portion 60 is illustrated. 3, reference numerals obtained by adding 40 to the reference numerals in FIG. 2 are assigned to members corresponding to the members in FIG.

In the belt system 70 of the comparative example, the contour shape of the tooth surface 60S corresponds to the pulley groove bottom surface 82B in a wide range around the vertex 60P. A gap corresponding to the first gap G ₁ (see FIG. 2) in the present embodiment is narrow, and a gap corresponding to the second gap G ₂ is not provided.

  Therefore, when the tooth portion 60 is engaged with the pulley groove 82, that is, when the tooth surface 60S is in the engagement position indicated by the solid line, the tooth surface 60S contacts almost the entire area of the pulley groove bottom surface 82B, and The apex 60P of the portion 60 is in contact with the center point 82P of the pulley groove bottom surface 82B. As described above, in the belt system 70 of the comparative example, the contact region 60C of the tooth surface 60S, that is, the region contacted by the pulley groove 82 when the tooth portion 60 is engaged is wide.

Furthermore, since the tooth surface 60S and the pulley groove 82 has a profile as described above, the tooth portion 60, the curve during the movement from the position shown by the curve L ₁ to the engaged position, and the engagement position L also during the movement to the position shown by _2, teeth 60 are in contact with the pulley 80.

  That is, while the tooth portion 60 moves to the engagement position, the tooth bottom surface 64 of the tooth portion 60 is in the first region 80A at the pulley groove 82 side end portion of the pulley tooth tip surface 80S, and the tooth surface 60S is the pulley groove 82. It contacts the upper second region 80B. Similarly, when the tooth portion 60 moves away from the engagement position, the tooth bottom surface 64 contacts the third region 80C and the tooth surface 60S contacts the fourth region 80D.

  In addition, the broken line which shows 1st-4th area | region 80A-D in FIG. 3 shows the position of the tooth surface 60S at the time of assuming that the tooth part 60 does not deform | transform when the tooth part 60 contacts the pulley groove | channel 82. . However, the first to fourth regions 80A to 80D are all exaggerated and greatly shown.

  As described above, in the belt system 70 of the comparative example in which the tooth portion 60 of the toothed belt contacts the pulley 80 in a wide range, unlike the present embodiment, there is a possibility that a large noise is generated when the toothed belt travels. is there.

  Next, the material and the like of the toothed belt of this embodiment will be described. Table 1 compares the material of the tooth rubber layer 12 and the core wire 22 (see FIG. 1) of the toothed belt 10 of Examples 1 and 2 and the processing method of the core wire 22 with the toothed belt of the comparative example. Show.

  In the toothed belt of the comparative example, E glass fiber is used as the material of the core wire 22, and chloroprene rubber (hereinafter referred to as CR) is used as the main tooth rubber layer material. Only the RFL process is applied to the core wire.

  On the other hand, in the toothed belt 10 of Examples 1 and 2, S glass (high-strength glass) fiber is used as the material of the core wire. The core wires 22 of Examples 1 and 2 are subjected to RFL treatment and an overcoat layer is formed on the outermost layer thereof. The overcoat layer is formed by immersing the core wire 22 in, for example, an isocyanate-based adhesive and then drying.

  The core wire 22 using S glass fiber is less likely to be stretched than the core wire using E glass fiber, and has high strength. The core wire 22 is more firmly bonded to the tooth rubber layer 12 and the back rubber layer 14 when the overcoat layer is further applied than when only the RFL treatment is applied to the core wire. As is clear from the above, it can be said that the toothed belt 10 of Examples 1 and 2 is less stretchable and has higher rigidity than the toothed belt of the comparative example.

  Furthermore, in the toothed belt 10 of Example 2, hydrogenated nitrile rubber (hereinafter referred to as HNBR) is used as the material of the tooth rubber layer 12. The material of the canvas is the same for both the comparative example and Examples 1 and 2.

  The CR of the tooth rubber layer material used in the comparative example and Example 1 has a hardness of A88, whereas the HNBR of the tooth rubber layer material of Example 2 has a hardness of A92 (both JIS K-6253). ). Therefore, although there is a difference in the prescription other than these main components, from the viewpoint of the tooth rubber layer material, the tooth rubber layer 12 of Example 2 is harder than the tooth rubber layer of Comparative Example and Example 1, It can be said that the rigidity is high.

  From the above, it is considered that the hardness and rigidity of the toothed belt are improved in the order of the comparative example, example 1, and example 2. Hereinafter, an evaluation test for confirming this point will be described. FIG. 4 is a diagram showing the results of a tensile test for the toothed belts of the comparative example and Example 1. FIG. 5 is a diagram showing the results of a test for evaluating the elasticity of the main component of the tooth rubber layer material.

  In the tensile test, the toothed belts of the comparative example and the example 1 were pulled around a pulley (not shown) under the same conditions. When tension was applied until each toothed belt broke, as shown in FIG. 4, the toothed belt of Example 1 was not easily stretched even when a greater tension was applied than the toothed belt of the comparative example. A large tension was required to break. As a result, as described above, it was confirmed that the toothed belt of Example 1 was less stretchable than the comparative example and was excellent in strength.

  On the other hand, as shown in FIG. 5, the elasticity of the tooth rubber layer material is a sheet having the same shape formed by using the CR of the comparative example, the first example, and the HNBR of the second example (see Table 1). It was evaluated by measuring the storage elastic modulus (Pa). This storage elastic modulus evaluation test was performed at a temperature of 80 ° C. and a frequency of 10 Hz for 120 minutes. As a result, it was confirmed that the HNBR sheet had a higher modulus than the CR sheet.

  From the test results shown in FIGS. 4 and 5, it was confirmed that the toothed belt was difficult to extend and the rigidity was high in the order of Comparative Example, Example 1, and Example 2.

  Next, a noise comparison test of a belt system in which a toothed belt and a pulley are combined will be described. Table 2 shows a combination of a toothed belt and a pulley in a belt system subjected to a noise comparison test.

  In the belt system of the comparative example, the toothed belt of the comparative example having the tooth portion 60 and the pulley 80 of the comparative example (see FIG. 3) are combined. In contrast, in the belt system of Example A, the toothed belt of the comparative example (see FIG. 3) and the pulley 40 of the example (see FIG. 2), and in the belt system of Example B, the toothed belt of Example 1. 10 (having the shape shown in FIG. 2 and using the material of Example 1 in Table 1) and the pulley 40 (see FIG. 2) of the example are combined.

  Similarly, the belt system of Example C includes the toothed belt of Example 2 (having the shape shown in FIG. 2 and using the material of Example 2 of Table 1) and the pulley 80 of the comparative example (see FIG. 3). ), The belt system of Example D includes the toothed belt 10 of Example 2 and the pulley 40 of Example. About these belt systems, the noise comparison test which measures and compares the noise level at the time of driving of a toothed belt was done.

  FIG. 6 is a diagram showing the results of a noise comparison test of the belt system. In the noise comparison test, the length of the toothed belt is 2100 mm and the rotational speed of the pulley is 3000 rpm. The noise level was measured at

  As a result, the noise of the belt system of the comparative example was the largest. This is because the toothed belt of the comparative example has low rigidity and the contact area 60C of the toothed portion 60 of the toothed belt is wide (see FIG. 3). This is because the deformation of the portion 60 has increased. In particular, the higher the torque when tooth skipping occurred, the greater the noise generated.

  On the other hand, in the belt system of Example A (see Table 2) using the pulley of the example, the noise is lower than that of the belt system of the comparative example. This is considered to be an effect due to the fact that the shape of the pulley groove 42 in the pulley 40 of the embodiment (see FIG. 2) reduces the meshing interference with the tooth portion of the toothed belt.

  Further, in the belt systems of Example B and Example C using the toothed belt 10 of Example 1 or Example 2, noise reduction is recognized. This is presumably because the use of the toothed belt of Example 1 or 2 having high rigidity and small elongation such as the tooth portion 20 can suppress the deformation of the tooth portion 20 and also prevent the meshing position from shifting.

  The test results of the belt systems of Example B (the toothed belt 10 of Example 1 and the pulley 40 of the example) and Example C (the toothed belt 10 of Example 2 and the pulley 80 of the comparative example) are compared. In the case of a high load (torque is 147 N · m), the noise in Example C is lower than that in Example B, and in the case of a low load (torque is 0 N · m, 49 N · m), there is an opposite tendency. In this way, at high loads, the hardness and rigidity of the toothed belt have a greater effect on the noise level than at the pulley shape, and the pulley shape has a greater effect at low loads. it is conceivable that.

  In the belt system of Example D (see FIG. 2) in which the toothed belt 10 of Example 2 and the pulley 40 of Example were combined, noise was further suppressed as compared with the above-described comparative example and Example. This is because the shapes of the tooth portion 20 and the pulley groove 42 are adapted to each other, greatly reducing meshing interference and preventing the deformation of the toothed belt 10 having high hardness and rigidity, particularly the deformation of the tooth portion 20. This is probably due to the effect.

  In particular, paying attention to the test results of Example C and Example D in which only the pulley is different, the pulley 40 of the example has the pulley 80 of the comparative example (see FIG. 3) depending on the shape of the pulley groove 42 (see FIG. 2). It can be seen that the meshing interference is reduced more. This is also clear from the comparison results of the comparative example and the belt system of Example A (see paragraphs [0051] and [0052]), in which only the pulleys are different, as described above.

  As described above, in the belt system of the present embodiment, it is necessary to withstand high meshing accuracy and a large load by using at least one of the toothed belt 10 of Examples 1 and 2 or the pulley 40 described above. Noise can be suppressed even when used in a severe environment.

  The material or the like of the toothed belt 10 is not limited to that in the above-described embodiment. For example, a tooth rubber layer material other than HNBR may be used. In particular, since the toothed belt 10 having high hardness and rigidity such as the tooth portion 20 is suitable for noise suppression, for example, the tooth rubber layer material of the toothed belt 10 of Example 2 (the hardness is A92 (JIS K-6253). )) Use of materials with higher hardness and rigidity is suitable. The material of the canvas 16, the core wire 22, and the like can be appropriately selected within a range in which the hardness and rigidity of the toothed belt 10 are not significantly reduced.

  Further, the pulley 40 can be applied to both the driving pulley and the driven pulley of the belt system 30.

It is a perspective view which fractures | ruptures and shows a part of toothed belt of this embodiment. In the belt system of this embodiment, it is sectional drawing which shows the state which the tooth | gear part of a toothed belt has engaged with the pulley groove | channel. It is sectional drawing which shows the belt system of the comparative example corresponding to FIG. It is a figure which shows the result of the tension test which made the toothed belt of a comparative example and Example 1 object. It is a figure which shows the result of the test which evaluated the elasticity of the main component of the tooth rubber layer material. It is a figure which shows the result of the noise comparison test of a belt system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Toothed belt 20 Tooth part 20C Compression area 20P Vertex 20S Tooth surface 22 Core wire 24 Tooth bottom 30 Belt system 40 Pulley 42 Pulley groove 42B Pulley groove bottom face (pulley groove bottom)
42T Inflection point G ₁ 1st gap G ₂ 2nd gap

Claims (14)

A belt system comprising a toothed belt having a round tooth shape and a pulley provided with a pulley groove with which the tooth portion is engaged,
The contour shape of the tooth portion and the pulley groove is such that when the tooth portion is engaged with the pulley groove, the pulley groove is on the apex side of the tooth portion with respect to the center of the tooth height on the tooth surface of the tooth portion. And compressing only the compression region in the pulley groove, providing a first gap between the tooth portion at the inflection point of the contour shape provided in the vicinity of the end of the pulley tooth tip surface in the pulley groove, The belt system is adjusted to provide a second gap between the apex of the pulley and the pulley groove bottom.   The compression region includes a region in the tooth surface where a distance from the apex of the tooth portion is 1/4 of the tooth height and a plane parallel to the tooth bottom surface of the toothed belt intersects. The belt system according to claim 1.   The belt system according to claim 1, wherein the pulley groove compresses the compression region in a direction of 45 ° with respect to a tooth bottom surface of the toothed belt.   The belt system according to claim 3, wherein a compression ratio of the tooth portion by the pulley groove is 0.5% or more and 3.0% or less based on a tooth height.   The belt system according to claim 4, wherein the compression ratio is 0.8%.   The belt system according to claim 1, wherein the size of the first gap is 0.5% or more and 3.0% or less of the belt pitch.   The belt system according to claim 6, wherein the size of the first gap is 1.0% of the belt pitch.   The pulley groove bottom side, which is the region on the pulley groove bottom side of the inflection point, has a curvature of the pulley tooth side region which is a region on the end side of the pulley tooth tip surface with respect to the inflection point in the pulley groove. The belt system according to claim 1, wherein the belt system is larger than a curvature of the region.   2. When the toothed belt is traveling so that the tooth portion engages with the pulley groove, only the compression region contacts the pulley groove on the tooth surface. Belt system.   A toothed belt used in the belt system according to claim 1.   The toothed belt according to claim 10, wherein the hardness of the rubber layer material forming the tooth portion is A92 (JIS K-6253) or more.   The toothed belt according to claim 10, wherein the toothed belt has an S-glass core wire.   The toothed belt according to claim 10, wherein the tooth portion is formed of a rubber layer material containing HNBR.   A pulley used in the belt system according to claim 1.

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