JPWO2013146362A1 - Cylindrical roller, motion guide device including the same, and rotary bearing - Google Patents

Abstract

While suppressing the occurrence of uneven contact, it has a sufficient allowable load, is easy to produce, and is arranged between a pair of raceway surfaces, rolls while applying a load, and has an outer peripheral surface that contacts the raceway surface. It is a cylindrical roller (3) having a single rotation axis that is formed in a columnar shape, and a recess (32) that faces the rotation center of the cylindrical roller (3) on both end faces located in the rotation axis direction. In the relationship between the ratio of the depth of the recess (32) to the diameter of the cylindrical roller (3) and the allowable load within the range in which the cylindrical roller (3) does not strike, the cylindrical roller (3) The depth of the recess (32) is set so that the ratio of the diameter to the depth of the recess (32) is equal to or greater than the value indicating the peak of the allowable load of the cylindrical roller (3).

Description

  The present invention relates to a cylindrical roller, a motion guide device including the cylindrical roller, and a rotary bearing.

  As the motion guide device, for example, a linear guide is known. The linear guide is assembled to the raceway member via a raceway member having a rolling surface formed along the longitudinal direction and a plurality of cylindrical rollers rolling on the raceway surface, and reciprocates along the raceway member. And a movable moving member. The moving member is provided with an infinite circulation path of cylindrical rollers, so that the moving member can move along the track member without being restricted in stroke.

  In the linear guide thus configured, for example, when an excessive moment is applied to the moving member, the rolling surface of the raceway member and the cylindrical roller are not parallel, and a component force is generated in the axial direction of the cylindrical roller. Therefore, the cylindrical roller is in a state of uneven contact, and there is a possibility that the function of the linear guide cannot be fully exhibited. Here, the uneven contact of the cylindrical roller means a state in which the stress at both ends of the cylindrical roller in the rotation axis direction exceeds the stress at the center in the rotation axis direction.

  In order to solve such a problem, in the conventional linear guide, the outer peripheral surface of the cylindrical roller is processed as an inclined surface that gradually slopes from the center in the rotation axis direction to both ends of the cylindrical roller, that is, the cylinder. The roller is crowned. By crowning the cylindrical roller, the entire outer peripheral surface of the cylindrical roller comes into uniform contact with the rolling surface of the raceway member only when a load is applied to the cylindrical roller. As a result, the surface pressure at both ends in the rotation axis direction of the cylindrical roller is substantially the same as the surface pressure at the center portion in the rotation axis direction, that is, the stress at both ends in the rotation axis direction does not exceed the stress at the center in the rotation axis direction. It becomes like this.

  However, the crowning process for the cylindrical roller is performed so that the entire outer peripheral surface of the cylindrical roller uniformly contacts the rolling surface of the raceway member when a specific design load is applied to the cylindrical roller. is there. That is, in the cylindrical roller subjected to crowning, only the outer peripheral surface in the vicinity of the central portion of the cylindrical roller is in contact with the rolling surface of the raceway member until a design load is applied to the cylindrical roller. For this reason, the contact area of the cylindrical roller with respect to the rolling surface of the track member is small until a predetermined load is applied to the cylindrical roller.

  In other words, the crowning process is to give the cylindrical roller an optimal shape that does not cause uneven contact when the design load acts on the cylindrical roller, and in an environment where a load smaller than the design load acts on the cylindrical roller. Then, the load which the said cylindrical roller can load will become small. On the other hand, when the load more than the design load is applied to the cylindrical roller, the above-mentioned unevenness naturally occurs. That is, the cylindrical roller subjected to the crowning process is optimized for a specific design load and cannot be said to be versatile.

  As means for compensating for such defects caused by crowning, hollow notches are provided on both end faces located in the direction of the rotation axis of the cylindrical roller, and when a load is applied to the cylindrical roller, the direction of the rotation axis of the cylindrical roller is reduced. Means have been devised to prevent the stress at both ends from increasing (Patent Document 1).

JP 2000-170771 A

  However, in the case of a cylindrical roller having hollow notches formed on both end surfaces in the direction of the rotation axis, the effect of reducing the uneven contact is certainly recognized, but depending on the shape of the notch, a sufficient allowable load may be applied. There is a case where uneven contact occurs without being obtained.

  The present invention has been made in view of such a problem, and the cylindrical roller of the present invention has an outer peripheral surface that is arranged between a pair of raceway surfaces and rolls while applying a load to contact the raceway surface. The cylindrical roller has a single axis of rotation, and at both end faces located in the direction of the axis of rotation, a recess is formed toward the center of rotation of the cylindrical roller. In the relationship between the depth ratio and the allowable load in the range where the uneven contact of the cylindrical roller does not occur, the ratio of the diameter of the cylindrical roller and the depth of the recess is not less than the value indicating the peak of the allowable load of the cylindrical roller. The depth of the recess is set.

  According to the cylindrical roller of the present invention, and the motion guide device and the rotary bearing provided with the cylindrical roller, it is easy to produce while having a sufficient permissible load while suppressing the occurrence of the above-mentioned offset and taking into account machining errors. It is possible.

It is a perspective view of the linear guide provided with the cylindrical roller which concerns on embodiment of this invention. It is a perspective view which shows the coupling body belt which arranged the cylindrical roller which concerns on embodiment of this invention. It is sectional drawing which shows an example of the recessed part with which the cylindrical roller which concerns on embodiment of this invention is provided. In the cylindrical roller shown in FIG. 3, it is sectional drawing which shows the modification of the said recessed part. It is a schematic diagram which shows the shaping | molding method of the recessed part with which the cylindrical roller which concerns on embodiment of this invention is provided. It is a schematic diagram for demonstrating the eccentric contact of a cylindrical roller. It is a distribution graph of the allowable load P with respect to the ratio X% in the cylindrical roller of the model 1 in which the angle θ is 0 °. It is a distribution graph of the allowable load P with respect to the ratio X% in the cylindrical roller of the model 1 in which the angle θ is 10 °. It is a distribution graph of the allowable load P with respect to the ratio X% in the cylindrical roller of the model 1 in which the angle θ is 20 °. It is a distribution graph of the allowable load P with respect to the ratio X% in the cylindrical roller of the model 1 in which the angle θ is 30 °. 6 is a correlation graph showing a relationship between the ratio X% in the roller of the analysis model 1 and the angle θ of the recess. It is a distribution graph of the allowable load P with respect to the ratio X% in the cylindrical roller of the model 2 in which the angle θ is 0 °. It is a distribution graph of the allowable load P with respect to the ratio X% in the cylindrical roller of the model 2 in which the angle θ is 10 °. It is a distribution graph of the allowable load P with respect to the ratio X% in the cylindrical roller of the model 2 in which the angle θ is 20 °.

  Hereinafter, a cylindrical roller and a motion guide device using the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a linear guide as a motion guide device provided with a cylindrical roller according to an embodiment of the present invention. The linear guide includes a track rail 1 in which a roller rolling surface 10 as a raceway surface on which a roller 3 as a cylindrical roller rolls is formed along a longitudinal direction, and the track rail 1 via a plurality of rollers 3. The moving block 2 is assembled and has an infinite circulation path for the roller 3. When the roller 3 rolls on the roller rolling surface 10 of the track rail 1 while circulating in the endless circulation path, the moving block 2 can freely move along the longitudinal direction of the track rail 1. It is possible.

  The track rail 1 is formed in a substantially rectangular cross section, and concave portions are formed on both side surfaces thereof. Roller rolling surfaces 10 of the roller 3 are formed above and below each recess, and four roller rolling surfaces 10 are formed in the entire track rail 1. On the other hand, a load roller rolling surface as a raceway surface on which the roller 3 rolls is formed on the moving block 2, and the load roller rolling surface and the roller rolling surface 10 of the track rail 1 are mutually connected. The rollers 3 face each other and constitute a loaded roller rolling path where the roller 3 rolls while being loaded between the moving block 2 and the track rail 1. The moving block 2 includes a return path in which the roller 3 rolls in an unloaded state in parallel with the load roller rolling path, and a direction changing path that connects one end of the return path and one end of the load roller rolling path. The endless circulation path of the roller 3 is formed by the load roller rolling path, the return path, and the pair of direction changing paths.

  As shown in FIG. 2, the rollers 3 arranged in the infinite circulation path included in the moving block 2 are arranged in a line at equal intervals on the flexible connecting belt 4. And incorporated into the endless circuit. The connecting body belt 4 is formed by injection molding of synthetic resin, and includes a plurality of spacers 41 interposed between the rollers 3 and a belt portion 42 that connects the spacers 41 in a row. Has been. The roller 3 may be inserted into the endless circulation path without being arranged on the connecting belt 4.

  In this linear guide, as described above, the roller 3 rolls on the load roller rolling path formed by the roller rolling surface 10 of the track rail 1 and the load roller rolling surface of the moving block 2 while applying a load. It is configured. When the roller 3 is simply formed in a cylindrical shape and the outer diameter surface is not subjected to crowning or the like as in a conventional linear guide, the stress at both ends in the rotation axis direction of the roller 3 is caused by the acting load. There is a risk that so-called unevenness exceeding the stress at the center in the rotation axis direction may occur.

  However, the roller 3 to which the present invention is applied has hollow concave portions on both end faces located in the rotation axis direction, and this configuration suppresses the occurrence of uneven contact. Below, the Example of the roller 3 to which this invention is applied is described using drawing. 3 and 4 are cross-sectional views of the roller 3 cut along a plane including its rotational axis. The roller 3 is formed in a cylindrical shape, and has an outer diameter surface 31 that contacts the roller rolling surface 10 of the track rail 1 and the load roller rolling surface of the moving block 2. Further, concave portions 32 are formed on both end surfaces of the roller 3 in the direction of the rotation axis O. The recess 32 has an angle θ with respect to each end surface in the rotation axis O direction of the roller 3, a distance from the end surface in the rotation axis O direction to the deepest portion, that is, a depth Dd of the recess 32 and a depth Dd with respect to the diameter Dw of the roller 3. The shape is set by the ratio X%, and depending on the angle θ, the depth Dd, and the ratio X%, it is formed in a conical shape having a triangular section as shown in FIG. 3 or a truncated cone shape having a trapezoidal section as shown in FIG. Is done.

  Thus, in the roller 3 to which the present invention is applied, the concave portions 32 are formed on both end surfaces in the direction of the rotation axis O. Therefore, in the case of the conical concave portion 32 by using the roller 3 over time, In the case of the truncated conical recess 32, stress concentrates on the corner located between the deepest portion and the peripheral surface, and cracks may be generated from these portions and the roller 3 may be damaged. is there. In order to prevent the occurrence of cracks, it is usual to increase the radius of curvature of the portion where stress concentration occurs, that is, the portion where the shape in the recess 32 changes rapidly.

  When the concave portion 32 is formed in a conical shape, it is only necessary to increase the radius of curvature of the deepest portion. Compared to this, when the concave portion 32 has a truncated cone shape, the shape of the concave portion 32 is sharp. There are a large number of regions that change, and the region where the radius of curvature is increased is wide. For this reason, when molding is performed to increase the radius of curvature of the stress concentration portion, the thickness of the roller 3 at both ends in the direction of the rotation axis O decreases, and as a result, the rigidity of the roller 3 may be impaired. From this point of view, when the recess 32 is formed in a truncated cone shape, as shown in FIG. 5, the corner located between the deepest portion 32 a of the recess 32 and the peripheral surface 32 b of the recess 32. That is, it is preferable that the cross-sectional shape of the stress concentration portion is formed in an arc along a tangent line that makes the deepest portion 32a and the peripheral surface 32b continuous without a step. This tangent line coincides with a single circle centered on a point Q where a line M perpendicular to the peripheral surface 32b of the recess 32 and a line N perpendicular to the deepest part 32a intersect.

  By forming the concave portion 32 in this way, the inner wall of the concave portion 32 is formed as a continuous spherical surface from the deepest portion 32a to the end surface of the roller 3 in the rotation axis O direction. When the load is applied, there is no portion where the stress is concentrated, and it is possible to prevent the roller from being damaged due to the occurrence of a crack. Further, the cross-sectional shape of the stress concentration portion is an arc along a tangent line that continues the deepest portion 32a of the concave portion 32 and the peripheral surface 32b of the concave portion 32 without a step, thereby preventing the concave portion 32 to suppress the occurrence of uneven contact. , The thickness of the end of the roller 3 in the direction of the rotation axis O can be increased, and the rigidity of the roller 3 itself can be increased accordingly.

  Considering the reduction in rigidity of the roller 3 due to the large molding area of the recess 32, the recess 32 is preferably formed in a truncated cone shape rather than being formed in a cone shape. Next, the inventor has determined that stress (contact) at both ends in the rotation axis direction of the roller 3 in which the concave portion 32 is formed in a truncated cone shape and the stress concentration portion is formed in a curved cross-sectional shape by the molding method described above. The surface pressure) exceeds the stress (contact surface pressure) at the center in the direction of the rotation axis O, and a so-called uneven contact was not devised by analysis.

  Here, the uneven contact of the rollers will be described with reference to FIG. In the graph in FIG. 6, the vertical axis represents the value of the contact surface pressure of the roller against the rolling surface of the track rail or the loaded roller rolling surface of the moving block, and the horizontal axis represents the rolling surface or the loaded roller rolling surface. The values of the coordinates of the contact part of the roller with are shown. In the horizontal axis value of FIG. 6, the minimum value 0 is the coordinate of the central portion in the rotation axis direction of the roller, and the maximum value of the horizontal axis indicates the coordinate of the end portion in the rotation axis direction of the roller.

  As a technique for determining the occurrence of uneven contact, first, the concave portion 32 is set to a constant shape, that is, the roller is specified for the angle θ, the depth Dd of the concave portion 32 and the ratio X%. The load is applied at an increase rate of. When the load acting on the roller is low, the contact surface pressure at both end portions in the rotation axis direction is lower than the contact surface pressure at the center portion in the rotation axis direction as shown in graph 3. In such a state, no uneven contact occurs in the roller. When the load acting on the roller is further increased, the contact surface pressure at both ends in the rotation axis direction shows the same value as that at the center portion in the rotation axis direction as shown in graph 2. In such a state, it can be said that no uneven contact has occurred in the roller. If the load acting on the roller is further increased, the contact surface pressure at both ends in the rotation axis direction exceeds the contact surface pressure at the center portion in the rotation axis direction as shown in graph 1. In other words, in a single roller, when the acting load becomes high, uneven contact is caused thereby.

  Here, the load amount of the roller is calculated in proportion to a value obtained by multiplying the contact surface pressure with the rolling surface by the contact area of the roller. Therefore, the area below each graph in FIG. 6 (the hatched area in FIG. 6 in the graph 2) is an area indicating the load amount of the roller. That is, in the roller in which the angle θ, the depth Dd of the concave portion 32, and the ratio X% are specified, the roller within a range in which uneven contact does not occur when the contact surface pressure distribution as shown in graph 2 is shown. The maximum allowable load is shown.

  The inventor of the roller 3 in which the concave portion 32 is formed has a distance L from one end surface to the other end surface in the direction of the rotation axis O of 10 mm and a roller diameter Dw of 6 mm (hereinafter referred to as “model 1”). ), And an allowable load in a range in which uneven contact does not occur in each model roller of the roller having the distance L of 7 mm and the diameter Dw of 4 mm (hereinafter referred to as “model 2”). As described above, the shape of the recess 32 is determined by the angle θ with respect to the end surface in the direction of the rotation axis O, the depth Dd, and the ratio X% of the depth Dd to the diameter Dw. The permissible load was analyzed in a range in which unevenness does not occur for each roller having a different ratio θ% of the depth Dd with respect to the diameter Dw in the rollers having different θs and the rollers having different angles θ. As this analysis means, a finite element method, that is, FEM analysis was used.

  For the analysis, FEM analysis software ANSYS (Cybernet System Co., Ltd .: registered trademark) manufactured by Cybernet System Co., Ltd. is used, and the roller 3 and the roller rolling surface 10 of the track rail 1 and the loaded roller rolling surface of the moving block 2 are modeled. And FEM analysis was performed. In the FEM analysis, the contact between the roller 3 and the roller rolling surface 10 of the track rail 1 and the loaded roller rolling surface of the moving block 2 was reproduced using a contact element. Further, as an analysis condition for the FEM analysis, a forced displacement is set in a direction in which the roller 3 is pressed against the roller rolling surface 10 of the track rail 1 and the load roller rolling surface of the moving block 2, and the contact surface pressure and allowable load are calculated. did. First, it was determined from the contact surface pressure whether or not the roller 3 was unevenly contacted, and then a forced displacement amount that maximized the allowable load was searched in a range where the uneven contact did not occur. This was repeated to determine the shape of the recess 32 to be the maximum allowable load.

  7A to 7D are distribution graphs of the allowable load P with respect to the ratio X% based on the FEM analysis result in the model 1 in which the angle θ and the ratio X% are different. FIG. 7A is an angle θ of 0 °, and FIG. Fig. 7C relates to the roller of model 1 in which the angle θ is 10 °, Fig. 7C shows the angle θ of 20 °, and Fig. 7D shows the angle θ of 30 °. That is, the plots in the respective distribution graphs shown in FIGS. 7A to 7D indicate the allowable load P in a range in which the uneven contact relating to each roller used in the analysis does not occur.

  As shown in FIG. 7A, among the rollers of model 1 in which the angle θ of the recess 32 with respect to each end face in the direction of the rotation axis O is 0 °, the ratio X% is 17% and the allowable load P is the maximum value. On the other hand, when the ratio X% relating to the roller of the model 1 is 13%, the allowable load P shows the lowest value. As shown in the distribution graph, in the roller of the model 1, it can be understood that the allowable load P of the roller rapidly increases in the range where the ratio X% is 13% to 17%. Hereinafter, in the distribution graph of the allowable load P based on the FEM analysis, a region where the value of the allowable load P increases rapidly is referred to as a “first region”. On the other hand, in the range where the ratio X% is 17% to 67%, the allowable load P of the roller gradually decreases. A region where the value of the allowable load P gradually decreases is referred to as a “second region”. Such distribution tendency of the allowable load P was observed for each roller in which the angle θ of the concave portion 32 with respect to each end surface in the direction of the rotation axis O in the roller of the model 1 is different as shown in FIGS. 7B to 7D.

  Considering the result of such FEM analysis, for example, in the roller 3 of the model 1 in which the angle θ shown in FIG. 7A is 0 °, when the required allowable load P is 10000 N, the ratio X% is represented in each graph. Even if the depth Dd of the recess 32 is set so as to exist in the first region, the required allowable load P can be sufficiently provided.

  However, in the first region of the graph in FIG. 7A, the ratio X% in the concave portion 32 only changes from 13% to 17%, that is, the depth Dd of the concave portion 32 changes within a minute range. Only by this, the numerical value of the allowable load P of the roller changes abruptly. For this reason, for example, when producing a roller that requires an allowable load of 10,000 N or more, if the ratio X% is set to 13% due to a processing error, the allowable load P of the roller becomes smaller than 10000 N, which is required. The allowable load condition may not be satisfied.

  That is, when setting the depth Dd of the recess 32 so that the ratio X% exists in the first region in the graph, it is necessary to increase the molding accuracy in consideration of the processing error due to the molding of the recess 32. Therefore, it takes time to form the recess 32 accordingly. From this point of view, when forming the roller to which the present invention is applied, it is not hard to set the depth Dd of the recess 32 so that the ratio X% exists in the first region in the graph.

  On the other hand, as described above, the allowable load of the roller gradually decreases in the second region of the graph, and the distribution tendency is gently inclined in the opposite direction to the first region. That is, in the second region of the graph, even if the set value of the depth Dd of the concave portion 32 changes in a wider range than the first region, there is no difference in the value of the allowable load P. For this reason, even when a processing error occurs after forming the recess 32 when the depth Dd of the recess 32 is set so that the ratio X% exists in the second region in the graph, the allowable load There is no possibility of forming a roller having an extremely low value of P.

  That is, rather than configuring the roller 3 to set the depth Dd of the recess 32 so that the ratio X% exists in the first area, the same ratio X% exists in the second area. If the depth Dd is set, it is not necessary to increase the molding accuracy, and accordingly, the molding of the concave portion 32 does not take much time. For each roller having a different angle θ where a similar tendency is observed in the distribution of the allowable load P, it is more preferable to set the depth Dd of the recess 32 so that the ratio X% exists in the second region. It can be grasped that the molding of 32 does not take time and effort.

  According to the FEM analysis, a similar distribution tendency is seen in the graph showing the allowable load P of each roller having a different angle θ, and as a result, any of the analyzed rollers has a critical value indicating the maximum allowable load. Obtained. Moreover, from such a distribution tendency, the result that it was preferable to set the depth Dd of the recessed part 32 so that the said ratio X% exists in a 2nd area | region in each roller was obtained. From these results, the inventor graphically showed the relationship between the ratio X% of the depth Dd of the recess 32 to the diameter Dw of the roller and the angle θ of the recess 32 with respect to each end face in the direction of the rotation axis O of the roller.

  FIG. 8 is a correlation graph showing the relationship between the ratio X% and the angle θ of the recess 32 in the model 1 roller. First, the graph shown in FIG. 8 will be described. Since the recesses 32 formed on both end faces of the roller 3 in the direction of the rotation axis O are formed so as not to penetrate, the straight line drawn with a two-dot chain line in the graph of FIG. The ratio X% is a line connecting the values of 75%. On the other hand, the curve drawn with a solid line is a curve connecting the values of the above-mentioned ratio X% at which the concave portion 32 is formed in a conical shape in each of the rollers having different angles θ. Further, the plot in the graph corresponds to the value of the ratio X% indicating the maximum allowable load in each roller having a different angle θ, that is, the connection point between the first region and the second region in each graph in FIG. The curve drawn with a dotted line is an approximate curve using these plots as indices.

  The vertical axis according to FIG. 8 indicates the value of the ratio X%, and the horizontal axis of the graph shown in FIG. 7 also indicates the ratio X%. That is, the horizontal axis in the graph of FIG. 7 and the vertical axis in FIG. 8 correspond to each other, and when FIG. 8 is grasped three-dimensionally, the vertical axis in the graph of FIG. It becomes the axis line shown. That is, in FIG. 8, in each roller having a different angle θ, the region where the ratio X% is lower than the value on the approximate curve corresponds to the first region of the graph in FIG. On the other hand, a region surrounded by the approximate curve, a two-dot chain line indicating a value that does not penetrate the concave portion 32, and a curve connecting the value of the ratio X% where the concave portion 32 is formed in a conical shape is shown in FIG. Corresponds to the second region of the graph.

  In other words, the region surrounded by the approximate region, a two-dot chain line indicating a value that does not penetrate the concave portion 32, and a curve that connects the value of the proportion X% where the concave portion 32 is formed in a conical shape. The roller 3 set to the above value can be easily produced without considering processing errors and the like while having sufficient rigidity and allowable load.

  According to the roller according to the present invention that employs the analysis results of the inventors described above, in the formation of the recess 32, the ratio X% of the depth Dd of the recess 32 to the diameter Dw of the roller 3 is determined by FEM analysis. By setting the depth Dd of the concave portion 32 so as to exist in the second region on the obtained graph, it is possible to produce a roller having a sufficient allowable load P in a range where no uneven contact occurs. In addition, there is no risk of producing a roller having an extremely low allowable load P due to processing errors, and the concave portion can be easily formed accordingly.

  9A to 9C are distribution graphs of the allowable load P with respect to the ratio X% based on the FEM analysis results of the rollers of the model 2 having different angles θ. 9A shows the analysis result of the roller of the model 2 in which the angle θ is 0 °, FIG. 9B shows the angle θ of 10 °, and FIG. 9C shows the angle θ of 20 °. Regarding the roller of the model 2, the same distribution tendency as the analysis result of the model 1 was observed in each roller having the different angle θ. That is, in the rollers having different angles θ, the distribution graph of the allowable load P shows that the distribution of the allowable load P of the roller rapidly increases as the ratio X% increases until the maximum allowable load is indicated. A first region and a second region where the distribution of the allowable load P of the roller gradually decreases as the value of the ratio X% increases from the value of the ratio X% indicating the maximum allowable load amount in the roller. Yes.

  That is, even in each roller of the model 2 having a different angle θ, by setting the depth Dd of the recess 32 so that the ratio X% exists in the second region, the occurrence of uneven contact is suppressed, It is possible to manufacture a roller having a sufficient allowable load P, and it is possible to easily produce the roller itself without any trouble in forming the concave portion.

  In addition, by using the roller according to the embodiment of the present invention in a motion guide device such as a linear guide, it is possible to secure a high steel load and a high load load while suppressing the occurrence of uneven contact.

  In the above embodiment, the roller according to the embodiment of the present invention has been described as being applicable to a linear guide as a motion guide device. However, the roller has a roller rolling path between the inner ring and the outer ring. It can be applied to a so-called rotary bearing provided. Even when the roller according to the embodiment of the present invention is applied to the rotary bearing or the like, it is possible to secure high steel and a high load load while suppressing the occurrence of uneven contact.

  In the above-described embodiment, the linear guide to which the roller according to the embodiment of the present invention can be applied has been described as having an infinite circulation path of the roller. It can be applied to a certain linear guide. Moreover, although the point which can apply the roller which concerns on embodiment of this invention to the linear guide as a motion guide apparatus was demonstrated, the said roller is applicable also to the curve guide apparatus in which the track rail 1 was formed in the shape of a curve. Is possible.

  In addition, the motion guidance apparatus according to the above-described embodiment includes a seismic isolation device, a system kitchen, various game machines, a medical machine from a machine tool, a semiconductor / liquid crystal manufacturing apparatus (for example, a mounting machine), and an industrial machine field such as a robot. It can be incorporated as a component part in a wide range of fields, including consumer products such as food machinery and transport equipment.

Claims (4)

A cylindrical roller (3) which is arranged between a pair of raceway surfaces, rolls while applying a load, has an outer peripheral surface (31) which contacts the raceway surface and is formed in a columnar shape and has a single rotation axis. ) And
On both end faces located in the direction of the rotation axis, a recess (32) directed toward the center of rotation of the cylindrical roller (3) is formed, and the ratio of the depth of the recess (32) to the diameter of the cylindrical roller (3) In the relationship with the allowable load in the range where uneven contact of the cylindrical roller (3) does not occur, the ratio of the diameter of the cylindrical roller (3) to the depth of the recess (32) shows the peak of the allowable load of the cylindrical roller (3). A cylindrical roller (3), characterized in that the depth of the recess (32) is set to be equal to or greater than the value shown. The following parameters,
Dw: Diameter of the cylindrical roller (3) Dd: Distance from the end face located in the rotation axis direction to the deepest portion (32a) of the concave portion (32) P: Allowable load X% within a range where no uneven contact occurs X: Cylindrical roller ( 3) With respect to the ratio of the distance Dd from the end face located in the direction of the rotation axis to the diameter Dw of 3) to the deepest part (32a) of the recess (32), the horizontal axis is the ratio X% and the vertical axis is the allowable load P When the graph is drawn, the graph is connected to the first region via the first region steeply inclined toward the plot indicating the maximum allowable load, and the plot indicating the maximum allowable load, and the first region. A second region that gently slopes in the opposite direction to the one region,
2. The cylindrical roller according to claim 1, wherein the Dd is set so that the ratio X% exists in a second region in the graph. A track rail (1) having a plurality of rolling surfaces (10) formed along the longitudinal direction, and a track surface facing the track surface (10), and the track is assembled to the track rail (1). In a motion guide device comprising a moving block (2) movable along the longitudinal direction of the rail (1),
A plurality of cylindrical rollers (3) according to claim 1 are arranged in a freely rolling manner in a gap between the raceway surface (10) of the raceway rail (1) and the raceway surface of the moving block (2). A motion guide device characterized by the above. In a rotary bearing comprising an outer ring having a raceway surface formed on an inner circumferential surface and an inner ring having a raceway surface opposed to the raceway surface on an outer circumferential surface,
2. A rotary bearing according to claim 1, wherein a plurality of cylindrical rollers according to claim 1 are arranged in a freely rolling manner in a gap where the raceway surface of the outer ring and the raceway surface of the inner ring face each other.

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