JP2005090633A - Toroidal continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the traction performances of a roller and a disk in a toroidal continuously variable transmission. <P>SOLUTION: A fine shape of the surface of either of both disk track faces 5b and 6c and the surface of a roller rolling face 7b comprises triangular fine recesses and projections formed of flat parts and dents in the rotating directions of both disks and the roller. The skewness Rsk thereof is -5 to 0. The averaged arithmetic mean roughness Ra of the track face of both disks and the rolling face of the roller is 0.01 to 0.12 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a toroidal-type continuously variable transmission used, for example, as a transmission for an automobile.

  Toroidal-type continuously variable transmissions have an input disk and an output disk with concave curved raceway surfaces so that the raceway surfaces face each other, and rollers are placed in a toroidal gap formed between both raceway surfaces. Thus, it is configured such that this is pressed against the raceway surface of each disk with a high load via a lubricating oil film. When the input disk rotates in such a toroidal type continuously variable transmission, torque is applied from the input disk to the output disk via the roller due to the shearing force of the lubricating oil film interposed between the rolling surface of the roller and the contact surface of each disk. Communicated. At this time, since the roller and each disk are rotating at high speed while being pressed against each other with a high load, the contact surface is under a severe condition of high surface pressure and high temperature, and an appropriate lubricating oil film is maintained on the contact surface. It was difficult. In order to solve such problems, it has been proposed to form fine irregularities or indentations on the rolling surface of the roller and both disk raceway surfaces for the purpose of oil accumulation effect. (See Patent Documents 1 and 2)

JP 2002-39306 A JP 2003-14067 A

  In the conventional toroidal-type continuously variable transmission described above, fine irregularities are formed on the roller rolling surface and both disk raceway surfaces, so that an appropriate lubricating oil film is maintained on the contact surface between the roller and the disk. In addition, it has the effect of preventing the true contact between the roller and the disk and improving the durability and traction performance by increasing the shearing force of the lubricating oil film. However, the traction effect between the roller and the disk depends on the shearing force of the lubricating oil film, and no attempt has been made to positively improve the traction performance by other means.

  In view of the circumstances as described above, the present invention improves the traction performance while maintaining the durability of the roller and the disk of the toroidal-type continuously variable transmission and not depending only on the traction effect due to the shear force of the lubricating oil film. Aimed.

  The toroidal continuously variable transmission of the present invention includes an input disk having a concave curved raceway surface on a side surface, a concave curved raceway surface disposed coaxially with the input disk and facing the track surface of the input disk. And an output disk having a toroidal gap formed between the raceway surfaces of the input disk and the output disk, rotating in contact with both raceway surfaces through the lubricating oil film, and both by the shearing force of the lubricating oil film. A toroidal-type continuously variable transmission having a plurality of rollers for transmitting torque between disks, wherein the fine surface of the roller rolling surface has triangular irregularities arranged in the rotational direction of the roller. The fine shape of either the input disk raceway surface or the output disk raceway surface is arranged with triangular irregularities in the rotational direction of the disk. It is characterized by having a have shape.

  In the toroidal type continuously variable transmission configured as described above, the following operations are obtained. Here, the contact portion between the disk raceway surface having fine triangular irregularities and the roller will be described. That is, the surface of the roller and the disk has a surface shape in which fine irregularities in a triangular shape are continuously arranged on the disk raceway surface or the roller rolling surface with respect to the rotation direction of the disk and the roller. ing. A lubricating oil film is formed between the contact surfaces of the roller and both disks. On the contact surface of the roller and the disk, the concaves and convexes are combined, and a gap is formed when both inclined surfaces forming the concaves and convexes approach each other. Here, when the disk and the roller rotate to transmit torque, the gap is narrowed and the pressure of the interposed lubricating oil film is increased. Then, by increasing the pressure of the lubricating oil film, a reaction force is generated and true contact can be prevented. This reaction force acts on the inclined surface forming the gap, and is a direction close to the tangential direction of the contact surface between the roller rolling surface and the disk raceway surface, and the direction along the circumferential direction. Therefore, sliding between the roller rolling surface and both disk raceway surfaces is prevented, and the traction performance is improved. That is, the traction performance between the roller rolling surface and the disk raceway surface can be improved by utilizing not only the shearing force of the lubricating oil film but also the reaction force generated by the shape of the contact surface. In addition, when the roller and both discs are in operation, dynamic pressure is generated between the roller rolling surface and the contact surfaces of both disc raceways due to the unevenness described above and the rotation of both discs or rollers, and the lubricating oil film The pressure is further increased. By increasing the pressure of the lubricating oil film, true contact is prevented between the roller and the disk as compared with the case where there is no unevenness on the surface, and the durability is improved.

  Further, in the toroidal continuously variable transmission, the fine shapes of the surface of the disk raceway surface and the roller rolling surface which are on the side of transmitting torque to the contact surface of the both disks and rollers are gently inclined. It is preferably a concavo-convex shape having a gradually inclined surface which is a triangular shape in which the surface and the steeply inclined surface are alternately arranged and rises with respect to the rotation direction. In this case, since the gap formed in the contact surface is formed by the steeply inclined surface, the acting reaction force acts in a direction closer to the tangential direction of the contact surface, and the traction performance can be improved. .

  In the toroidal continuously variable transmission, the fine shapes of the surface of the disk raceway surface and the roller rolling surface, which are the sides where the torque is transmitted from the mating surface of the both disks and rollers, are slightly inclined and steep. It is preferable that the surface has a triangular shape in which the inclined surfaces are alternately arranged, and has an uneven surface having a gently inclined surface that is tapered downward with respect to the rotation direction. In this case, since the gap formed in the contact surface is formed by the steeply inclined surface, the acting reaction force acts in a direction closer to the tangential direction of the contact surface, and the traction performance can be improved. .

  Further, in the process of earnestly researching the improvement in durability and traction performance of the roller and disk of the toroidal-type continuously variable transmission, the present inventors are a surface roughness parameter that is not listed in the conventional example, skewness. It has been found that the relationship between (Rsk) and arithmetic surface roughness (Ra) greatly affects the durability and traction performance of the roller and disk. That is, in the toroidal-type continuously variable transmission described above, the arithmetic average roughness (Ra) of both the disk raceway surfaces and the rolling surface of the roller is 0.01 to 0.12 μm, and has the irregularities. The skewness (Rsk) of the disk raceway surface and the rolling surface of the roller is preferably −2 to 0. The reason why the skewness (Rsk) is set to -2 to 0 is that when the skewness (Rsk) is increased in the direction of a positive value from 0, the height of the convex portion on the surface roughness is increased, and the aggression against the counterpart member is increased. This is because there is a possibility that surface origin peeling will occur from the convex portion. Further, when the skewness (Rsk) is made smaller in the negative direction than -2, since the concave portion of the triangular concave and convex portions is small and deep, the effect of increasing the lubricating oil film pressure cannot be expected and peeling occurs from the deep concave portion. This is because there is a possibility. By setting the skewness (Rsk) to −2 to 0, it is possible to effectively improve both the durability and traction performance of both disks and rollers.

  The present invention also includes an input disk having a concave curved raceway surface on a side surface, an output disk having a concave curved raceway surface disposed coaxially with the input disk and facing the raceway surface of the input disk, A plurality of which are arranged in a toroidal gap formed between the raceway surfaces of the input disk and the output disk, rotate in contact with both raceway surfaces via an oil film, and transmit torque between both disks by the shear force of the oil film A toroidal-type continuously variable transmission having at least one of the rollers, wherein a fine shape of at least one of the disk raceway surface and the rolling surface of the roller has a shape including a flat portion and a depression, and its skewness ( Rsk) is −5 to 0, and the arithmetic average roughness (Ra) of both the disk raceway surfaces and the rolling surfaces of the rollers is 0.01 to 0.12 μm.

  In the toroidal-type continuously variable transmission configured as described above, the fine dents formed on at least one of both the disk raceway surfaces or the roller rolling surfaces have the above skewness (Rsk) and arithmetic mean roughness (Ra). ), The necessary lubricating oil can be secured on the contact surfaces of both disk raceways or the rolling surfaces of the rollers. Furthermore, since the area of the flat portion that contacts between the roller and the disk decreases due to the presence of the depression, the surface pressure in the minute region of the contact surface increases. Thereby, the lubricating oil film pressure interposed on the contact surface increases, and accordingly, the kinematic viscosity of the lubricating oil film increases. These effects can prevent the true contact between the roller and the disk and improve the traction characteristics. The reason why the skewness (Rsk) is in the range of -5 to 0 is that the effect of oil accumulation cannot be expected when the skewness (Rsk) is 0 or more, and when the skewness (Rsk) is -5 or less, the shape of the surface has a deep dent. This is because the strength of the surface is reduced and surface-origin separation may occur. By setting the skewness (Rsk) to -5 to 0, it is possible to effectively improve both the durability and traction performance of both disks and rollers.

  According to the toroidal-type continuously variable transmission of the present invention configured as described above, the durability of the roller and the disk can be improved by setting the fine shape of both the disk raceway surfaces or the rolling surface of the roller to the above-described shape. And traction performance can be improved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, a case where a full toroidal continuously variable transmission is configured will be described as an example. FIG. 1 is a schematic cross-sectional view showing a main part of a toroidal type continuously variable transmission which is a first embodiment of the present invention. In the drawing, the variator 1 of the toroidal-type continuously variable transmission according to the present embodiment is provided with an input shaft 3 that is connected to an output shaft (not shown) of an engine that is a power source of the vehicle and is rotationally driven. The input disks 5 are supported in the vicinity of both ends.

  A concave curved raceway surface 5b is formed on one side surface of each input disk 5, and a spline hole 5a having a plurality of grooves is formed on the inner periphery thereof. The input disk 5 is assembled to the input shaft 3 so as to be integrally rotatable by coupling the spline hole 5a to a spline shaft 3a provided in the input shaft 3. Further, each input disk 5 is restricted from moving away from each other by a locking ring 51 fixed to the input shaft 3.

  An output portion 6 including an output member 6a and an output disk 6b supported by the output member 6a so as to be integrally rotatable with each other is relatively rotated with respect to the input shaft 3 at the axial center portion of the input shaft 3. It is provided freely. A concave curved track surface 6c is formed on one side surface of the output disk 6b facing the track surface 5b of the input disk 5. A sprocket gear 6e that meshes with the chain 6d is formed on the outer periphery of the output member 6a, and power is extracted to the outside through the chain 6d.

  The output disk 6b is incorporated into the output member 6a in a state in which fine movement in the axial direction is allowed, and a back-up plate 6h is disposed on the back surface thereof with a gap 6g. The gap 6g is sealed by a casing 6f and a seal (not shown). By supplying hydraulic pressure to the gap 6g from the hydraulic power source 9, the output disk 6b is urged toward the opposing input disk 5 to load the gap 6g. Has been added.

  A space between the raceway surface 5b of the pair of input disks 5 and the raceway surface 6c of the output disk 6b facing each other is configured as a toroidal gap, and each toroidal gap has a plurality of, for example, three disc shapes. The rollers 7 are arranged at equal circumferences. For example, traction oil (lubricating oil) is supplied as a lubricant between the roller 7 and the raceway surfaces 5b and 6c. In FIG. 1, only one roller 7 disposed in each toroidal gap is shown for the sake of simplification of the drawing. Further, as shown by the solid line in FIG. 1, each of the rollers 7 is at a position on the raceway surfaces 5b and 6c where the toroidal gap is the maximum dimension in the opposing direction of the raceway surfaces 5b and 6c. It is arranged so as to be able to roll, and is rotatably supported by the carriage 8 and its rotation shaft 7a is rotatably supported. A driving force by hydraulic pressure is applied to the carriage 8 in a direction crossing the paper surface of FIG.

  In the variator 1, when the pair of input disks 5 rotate, the rotation is transmitted from the input disk 5 to the output disk 6 b via the three rollers 7 on the left and right. When a reaction force is applied to the carriage 8, torque is transmitted by a force that shears the oil film between the roller 7 supported by the carriage 8 and both the disks 5 and 6 b. The roller 7 inclines the rotating shaft 7a in order to eliminate the imbalance between the torque and the rotational speed from the output disk 6b. As a result, the position of the roller 7 changes as indicated by the two-dot chain line in FIG. 1, and the gear ratio between the disks 5 and 6b changes continuously.

  A sectional view and a plan view of the roller 7 in the variator 1 are shown in FIG. The roller rolling surface 7b which is the outer peripheral surface of the roller 7 is in contact with the raceway surfaces 5b and 6c of both disks. It has a triangular shape in which the surfaces are alternately arranged, and has fine irregularities having a gently sloping surface that is tapered downward with respect to the rotation direction. At this time, the arithmetic average roughness (Ra) of the roller rolling surface 7b is 0.01 to 0.12 μm, and the skewness (Rsk) is set to −2 to 0. Next, a sectional view and a plan view of the input disk 5 are shown in FIG. The input disk raceway surface 5b contacts the roller rolling surface 7b, and the surface of the range D indicated by the alternate long and short dash line in the figure has a triangular shape in which gently inclined surfaces and steeply inclined surfaces are alternately arranged with respect to the rotation direction. And the fine unevenness | corrugation which has a gently sloping surface which goes up with respect to the rotation direction is formed. At this time, the arithmetic mean roughness (Ra) of the disk raceway surface 5b is 0.01 to 0.12 μm, and the skewness (Rsk) is set to −2 to 0. Further, the range where the output disk raceway surface 6c contacts the roller rolling surface 7b is a triangular shape in which gently inclined surfaces and steeply inclined surfaces are alternately arranged with respect to the rotation direction, Fine irregularities having a gently sloping surface with a tip-down shape are formed. Fine irregularities are formed. At this time, the arithmetic mean roughness (Ra) of the disk raceway surface 6c is 0.01 to 0.12 μm, and the skewness (Rsk) is set to −2 to 0.

  FIG. 4 shows a schematic diagram of a fine region of the cross section of the contact surface between the roller rolling surface 7b and the input disk raceway surface 5b when the toroidal continuously variable transmission is in an operating state. The arrows in the figure indicate the rotation directions of the roller rolling surface 7b and the input disk raceway surface 5b. The roller rolling surface 7b is formed with a gently sloping surface 7c that descends toward the rotation direction of the roller 7 and a steeply inclined surface 7d that descends toward the rotation direction of the roller 7, and these are By arranging them alternately, fine triangular irregularities are formed on the roller rolling surface 7b. On the disk raceway surface 5b, a gently inclined surface 5c that rises upward in the rotation direction of the disk 5 and a steeply inclined surface 5d that decreases in the rotation direction of the disk 5 are formed. Similar to the surface 7b, fine triangular irregularities are formed on the disk raceway surface 5b. A lubricating oil film is formed between the roller 7 and the input disk 5.

  Here, when the input disk 5 rotates to transmit torque to the roller 7, the gap shown by E in the figure formed by the steeply inclined surfaces 5d and 7d is narrowed, and the lubricating oil film present in the gap E The pressure of is increased. By increasing the pressure of the lubricating oil film, a reaction force acts, and the true contact between the roller rolling surface 7b and the input disk raceway surface 5b can be prevented. The reaction force acts between the steeply inclined surfaces 5d and 7d, and the direction of the reaction force is close to the tangential direction of the contact surface of the roller rolling surface 7b and the input disk raceway surface 5b. Thus, since it acts in a direction along the circumferential direction, sliding between the roller rolling surface 7b and the input disk raceway surface 5b is prevented, and the traction performance is improved. Further, the fine irregularities formed on the rolling surface 7b of the roller 7 and the disk raceway surface 5b are formed so as to have a surface shape in which triangular irregularities are continuously arranged in the rotation direction. In the rotation, the unevenness becomes resistance to the lubricating oil. As a result, rotation of the roller 7 and the disks 5 and 6b generates dynamic pressure, and the pressure of the lubricating oil film between the contact surfaces of the roller rolling surface 7b and the input disk raceway surface 5b is increased. Can be prevented.

  Here, the skewness (Rsk) is a value (dimensionless number) indicating symmetry with respect to the center line of the amplitude distribution curve of the roughness curve defined in JIS B0601 and is expressed by the following equation.

Rq is the root mean square roughness, n is the number of samples of measurement data, y _i is the height from the center line of the roughness curve of the i-th measurement data, and l _r is the sample length. FIGS. 5A and 5B show two roughness curves having the same arithmetic average roughness (Ra). As shown in FIG. 5A, when the amplitude of the surface roughness is biased upward, the skewness is negative (<0). Such a state indicates that a deep recess exists. Then, as shown in FIG. 5B, when the amplitude of the surface roughness is biased downward, the skewness is positive (> 0), indicating that a high convex portion exists. When the amplitude of the surface roughness is substantially equal in the vertical direction, the skewness is zero (0). Skewness (Rsk) shows good wear resistance in the negative case where there are few high convex portions from the roughness center line and there are deep concave portions.

  In the roller rolling surface 7b, the skewness (Rsk) is set to -2 to 0. When the skewness (Rsk) is increased in a positive direction from 0, the height of the convex portion on the surface roughness increases, This is because, in addition to increasing the attacking property to the member, there is a possibility that surface-origin separation will occur from the convex portion. Further, if the skewness (Rsk) is made smaller in the negative direction than −2, the number of the concave portions in the triangular concave / convex portions is reduced, so that the effect of increasing the lubricating oil film pressure cannot be expected. By setting the skewness (Rsk) to −2 to 0, it is possible to effectively improve both the durability and traction performance of both disks and rollers.

  The triangular rolling irregularities of the roller rolling surface 7b and the disk raceway surfaces 5b, 6c are further reduced to the following after the arithmetic average roughness (Ra) of the roller rolling surface 7b is 0.12 μm or less. It was formed by performing the processing shown. That is, when the grinding tool was brought into contact with the roller rolling surface 7b, chatter vibration was generated in the grinding tool, and the contact between the surface of the roller rolling surface 7b and the grinding tool was interrupted. Grinding is performed by repeatedly grinding the grinding tool so as to make fine scratches on the workpiece surface when viewed microscopically. Here, when the contact between the grinding tool and the roller outer peripheral portion 7b is interrupted, the grinding tool tip gradually cuts deeply from the roller surface in the process of contacting the grinding tool and the roller from a separated state. In addition, a gently inclined surface is formed. Then, when the tip of the grinding tool leaves again, a steeply inclined surface is formed. By repeating this continuously, triangular irregularities in which gently inclined surfaces and steeply inclined surfaces are alternately arranged with respect to the rotation direction were formed. Further, after forming the irregularities, the roller rolling surface 7b was subjected to finish polishing again to smooth the tops of the convex and concave portions formed on the surface, and at the same time, adjusted to a predetermined surface roughness.

  Note that the shape of the unevenness can be adjusted to a predetermined shape by adjusting the grinding tool material, type, shape, applied pressure, roller rotation speed, and the like, which are parameters during grinding. In addition, although the above-described irregularities are formed by utilizing chatter vibration of the grinding tool that occurs during grinding, this time, similar irregularities can also be formed by actively vibrating the grinding tool.

  FIG. 6 schematically shows the relationship between the rotation direction and the concavo-convex shape when the roller rolling surface and the disk raceway surface come into contact with each other. The arrows in the figure indicate the rotation directions of the roller and the disk. 6A, the relationship between the rotational direction of the roller 7 and the input disk 5 and the concavo-convex shape, that is, the input disk raceway surface 5b on the torque transmitting side rises forward with respect to the rotational direction. The roller rolling surface 7b, which is the side to which torque is transmitted, is formed into a triangular unevenness having a gently inclined surface 7e that is tapered downward with respect to the rotational direction. When combined, the best effect is obtained. In this case, since the gap that generates the reaction force that contributes to improving the traction performance is formed by the steeply inclined surfaces, the acting reaction force is the tangent of the contact surface most. This is because it works in a direction close to the direction.

  Further, the relationship shown in FIG. 6B, that is, the roller rolling surface 7b on the torque transmitting side is formed into a triangular concave / convex shape having a sloping surface 7e that descends with respect to the rotation direction, and torque is transmitted. In the case where the output disk raceway surface 6c, which is the rotating disk, is combined as triangular irregularities having an inclined surface 6i that is tapered downward with respect to the rotation direction, one of the above-mentioned gaps is a steeply inclined surface and the other is gently inclined Since it is formed by the surface, the direction of the acting reaction force acts in a direction deviating from the tangential direction of the contact surface as compared with the case of FIG. From this, although it does not reach in the case of Fig.6 (a), since reaction force is obtained, the effect of the improvement of traction performance is acquired. Also, as shown in FIGS. 6C and 6D, the roller rolling surface 7b is formed with triangular irregularities that are not significantly different in the inclination of the adjacent inclined surfaces 7f and 7g, and the other disk track. Even if the surface has triangular irregularities in which gently inclined surfaces and steeply inclined surfaces are alternately arranged, a gap is formed by the inclined surfaces on the contact surface, so the effect of improving traction performance Is obtained. The other possible combinations of triangular shape and rotational direction are not as good as in the case of FIG. 6A, but if a gap is formed between the inclined surfaces at the contact surface, the effect of improving the traction performance is can get.

  Next, a second embodiment of the present invention will be described. As in the first embodiment, the case where the full toroidal continuously variable transmission shown in FIG. 1 is configured will be described as an example. Since the main configuration is the same as that described in the first embodiment, a description thereof will be omitted. The characteristic configuration in the second embodiment will be described below.

  In the second embodiment, the fine shape of the surface of the range B on the roller rolling surface 7b shown in FIG. 2 and the range D on the input disk raceway surface 5b shown in FIG. 3 has a shape composed of a flat portion and a depression. The arithmetic average roughness (Ra) of the surface is in the range of 0.01 to 0.12 μm, and the skewness (Rsk) is set in the range of −5 to −0. Similarly, the track surface 6c of the output disk 6b has an arithmetic average roughness (Ra) of 0.01 to 0.12 μm and a skewness (Rsk) of −5 to −0.

  FIG. 6 shows a schematic diagram of a fine region of the cross section of the contact surface between the roller rolling surface 7b and the input disk raceway surface 5b at this time. The arrows in the figure indicate the rotation directions of the roller rolling surface 7b and the input disk raceway surface 5b. The roller rolling surface 7b is composed of a flat portion 7e and a recessed portion 7f. Similarly, the input disk raceway surface 5b includes a flat portion 5e and a recessed portion 5f. Both form a lubricating oil film between them and rotate in the direction of the arrow in the figure while being pressed against each other with a large load. At this time, the indented portions 5f and 7f have an oil sump effect, and the lubricating oil is retained therein, thereby preventing the lubricating oil on the contact surface from being insufficient. Further, the contact surfaces of the roller rolling surface 7b and the input disk raceway surface 5b are respectively carried by the flat portions 7e and 5e, and the contact area is reduced as compared with the case where there is no depression. Surface pressure increases. As a result, the lubricant film pressure interposed on the contact surface increases, and it is possible to prevent true contact between the roller and the disk and to improve the traction performance. Of course, the same effect can be obtained with the contact surface between the roller rolling surface 7b and the output disk raceway surface 6c.

  The reason why the skewness (Rsk) of the roller rolling surface 7b is set in the range of −5 to −0 is that if the skewness (Rsk) is 0 or more, the effect of oil accumulation cannot be expected. This is because the indentation becomes a shape like a deep scratch, the strength of the surface is lowered, and surface-origin separation may occur. By setting the skewness (Rsk) to -5 to 0, it is possible to maintain the effect of oil accumulation even during high-speed operation at a high rotational speed, and both the durability and traction performance of both disks and rollers are effective. Can be improved. It should be noted that the same effect can be obtained by forming the above-described recess in either one of the disk raceway surfaces 5b and 6c or the roller rolling surface 7b.

  Table 1 below shows the results of an experimental investigation of the influence of the life due to the surface roughness of the roller rolling surface and both disk raceways performed by the present inventors. In Table 1, high-carbon bearing steel is used for the rollers and disks used in the examples and comparative examples, and the roller rolling surface and the disk raceway surface are surfaces as shown in the second embodiment. The fine shape was a shape composed of a flat part and a hollow part. Furthermore, by adjusting parameters such as the density and depth of the indented portion, a predetermined surface roughness was obtained and the test was performed.

  The product according to the example has an arithmetic average roughness (Ra) of 0.12 μm below the roller rolling surface and the disk raceway surface, a value less than 0.06 to 0.08 μm, and a value below 0 (skewness (Rsk) 0). The test conditions were adjusted to 8 to -3.3, and the test conditions were a test time of 95 hours, a Hertz surface pressure of 3.3 GPa, and a rotation speed of 2000 rpm. In addition, the product of Comparative Example 1 has a value exceeding 0.12 μm arithmetic average roughness (Ra) of the roller rolling surface and the disk raceway surface, and a value below 0.13 to 0.16 μm and skewness (Rsk) 0. The test conditions were adjusted to -0.5 to -4.0, and the test conditions were a test time of 100 hours, a Hertz surface pressure of 3.3 GPa, and a rotation speed of 1000 rpm. In Comparative Example 2, the roller rolling surface and the disk raceway surface have an arithmetic average roughness (Ra) exceeding 0.12 μm, 0.19 to 0.21 μm, and a value exceeding Skewness (Rsk) 0. The test conditions were adjusted to 2 to 0.5, and the test conditions were a test time of 100 hours, a Hertz surface pressure of 3.3 GPa, and a rotation speed of 2000 rpm.

  From Table 1, it can be confirmed that the example product having an arithmetic average roughness (Ra) of less than 0.12 μm and a skewness (Rsk) of less than 0 does not cause delamination on the raceway surface of the disk in a test time of 95 hours. It was. On the other hand, although the skewness (Rsk) is smaller than 0, the arithmetic average roughness (Ra) is greater than 0.12 μm and one comparative example product, and the arithmetic average roughness (Ra) is larger than 0.12 μm. In the comparative example 2 products in which Rsk) is greater than 0, surface-origination peeling occurred. That is, when a fine dent is formed on the surface, the arithmetic average roughness (Ra) of the roller rolling surface and the disk raceway surface is 0.12 μm or less, and the skewness (Rsk) is set to 0 or less. From the above test results, it was found that surface-origin peeling was prevented and durability was improved.

  As described above, according to the toroidal type continuously variable transmission of the present invention, the durability of the roller and the disk can be improved by setting the fine shape of both the disk raceway surfaces or the rolling surfaces of the rollers to the predetermined shape described above. And traction performance can be improved.

It is the schematic which shows the variator part of the toroidal type continuously variable transmission by one Embodiment of this invention. (A) is roller sectional drawing of the said variator, (b) is the same top view. (A) is a sectional view of the input disk of the variator, and (b) is a plan view thereof. It is a schematic diagram of the fine area | region of the contact surface cross section of a roller rolling surface and an input disk track surface. It is a roughness curve and amplitude distribution curve for demonstrating skewness (Rsk). It is the schematic diagram which showed the relationship between the rotation direction at the time of a roller rolling surface and a disk track surface contacting, and uneven | corrugated shape. It is a schematic diagram of the fine area | region of the contact surface cross section of the roller rolling surface and input disk track surface in 2nd embodiment.

Explanation of symbols

5 Input disk 5b Track surface 5c Slightly inclined surface 5d Steeply inclined surface 5f Flat portion 5g Recessed portion 6b Output disk 6c Track surface 7 Roller 7b Rolling surface 7c Slowly inclined surface 7d Steeply inclined surface 7h Flat portion 7i Recessed portion

Claims (5)

An input disk having a concavely curved track surface on a side surface, an output disk having a concavely curved track surface disposed coaxially with the input disk and facing the track surface of the input disk, and the input and output disks A plurality of rollers arranged in a toroidal gap formed between the respective raceway surfaces, rotating in contact with both raceway surfaces via the lubricating oil film, and transmitting torque between the two disks by the shearing force of the lubricating oil film; A toroidal continuously variable transmission having
The surface of the roller rolling surface has a fine shape in which triangular irregularities are arranged with respect to the rotation direction of the roller, and either the input disk raceway surface or the output disk raceway surface The toroidal-type continuously variable transmission has a shape in which triangular irregularities are arranged in the rotational direction of the disk.   Of the two disks and rollers, the fine shapes of the surfaces of the disk raceway surface and the roller rolling surface, which are the sides that transmit torque to the mating surfaces that come into contact with each other, are arranged with gentle and steeply inclined surfaces alternately arranged. 2. The toroidal continuously variable transmission according to claim 1, wherein the toroidal continuously variable transmission has a triangular shape and has a gradually inclined surface that rises with respect to the rotational direction.   Of the two discs and rollers, the fine shapes of the disc raceway surface and the roller rolling surface, which are the sides to which torque is transmitted from the mating contact surface, are triangular shapes in which gentle and steeply inclined surfaces are alternately arranged. The toroidal continuously variable transmission according to claim 1 or 2, wherein the toroidal-type continuously variable transmission has a shape and an uneven surface having a gently sloping surface that descends downward with respect to the rotation direction.   The arithmetic mean roughness (Ra) of both the disk raceway surfaces and the rolling surface of the roller is 0.01 to 0.12 μm, and the skewness of the disk raceway surface having the irregularities and the rolling surface of the roller. The toroidal continuously variable transmission according to any one of claims 1 to 3, wherein (Rsk) is -2 to 0. An input disk having a concavely curved track surface on a side surface, an output disk having a concavely curved track surface disposed coaxially with the input disk and facing the track surface of the input disk, and the input and output disks Are arranged in a toroidal gap formed between the respective raceway surfaces, rotate in contact with both raceway surfaces via an oil film, and have a plurality of rollers that transmit torque between both disks by the shear force of the oil film A toroidal-type continuously variable transmission,
The fine surface shape of at least one of the disk raceway surface and the rolling surface of the roller has a shape composed of a flat portion and a depression, and its skewness (Rsk) is -5 to 0. A toroidal continuously variable transmission characterized in that the arithmetic average roughness (Ra) of the rolling surface of the roller is 0.01 to 0.12 μm.

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