JP5259455B2 - Flat sliding mechanism - Google Patents

Description

  The present invention relates to a planar sliding mechanism.

  The planar sliding mechanism that slides between the opposing planes is a thrust bearing used in a dynamic mechanism such as an automobile, or a linear sliding mechanism represented by a guide mechanism of a machine tool, depending on the application. Has been used.

  Here, as a linear motion sliding guide mechanism, for example, in Patent Document 1 below, a plurality of groove shapes with different depths are formed on one or both of the sliding surfaces for the purpose of improving the lubricity between the sliding surfaces. Have been proposed in which the recesses are formed in a direction perpendicular to the sliding direction.

  Further, as a thrust bearing surface structure, a bearing surface structure described in Patent Document 2 has been proposed. This bearing surface structure is intended to efficiently supply oil to the entire bearing surface, and is radially downstream of the oil supply groove extending radially, shallower than the oil supply groove and radially toward the downstream side. A tapered oil introduction groove is formed in which the circumferential groove depth becomes shallow.

JP 2002-235852 A JP 2008-144864 A

  The groove-like recesses disclosed in Patent Document 1 are independent from each other, and there is no mechanism for supplying lubricant to the recesses. It is difficult to expect the required oil film forming effect unless the conditions are supplied in abundance. In particular, in the case of a sliding linear motion guide mechanism having an open sliding plane, such as a sliding linear motion guide of a machine tool, a good oil film can be formed even if the technique according to Patent Document 1 is applied. Is difficult.

  In the thrust bearing surface structure disclosed in Patent Document 2, a relatively thick oil film is formed by the high oil drawing capacity of the tapered oil introduction portion. However, in the case of the oil introduction part that focuses on only the oil pulling force in this way, it is difficult to form an oil film of sufficient thickness, such as when the load of the mating member is large or the sliding speed is slow Then, the fluctuation of the oil film thickness becomes large, and the stability of the oil film thickness is lacking. Even when an oil film having a sufficient thickness is formed, the oil film thickness is likely to fluctuate due to speed fluctuations and load fluctuations, and sufficient oil film rigidity cannot be obtained. .

  In view of the above circumstances, in the present specification, it should be solved by the present invention to provide a plane sliding mechanism that has a small oil film thickness variation and excellent oil film rigidity regardless of the sliding speed and the magnitude of the load. Technical issue.

The present invention has been made to solve the above problems. In other words, the plane sliding mechanism according to the present invention is a plane sliding mechanism for performing relative sliding between opposing planes via a film of lubricating fluid, and either plane has an opposing plane. A deep groove for supplying a lubricating fluid therebetween and a shallow groove shallower than the deep groove are provided, and the shallow grooves are arranged in parallel with periodicity, and the plurality of shallow grooves arranged in parallel are deep grooves at one end. Majiwa Rutotomoni Ri other rises towards one of the flat at the end contact, and that they are arranged in a direction inclined at an inclination angle of less than parallel or 90 ° to the sliding direction of the opposite other plane Is characterized by In this case, “arranged in parallel with periodicity” means that the shallow grooves are arranged in parallel so that a combination of a plurality of types of shallow grooves having different depth dimensions, width dimensions or longitudinal dimensions appears periodically. In addition to the above-described ones, those in which shallow grooves of the same shape are arranged in parallel at a constant interval, and those in which the shallow grooves are arranged in parallel with a predetermined interval are included.

  The present invention has been made by paying attention to the relationship between the depth dimension of the groove provided on the sliding plane and the thickness dimension of the lubricating fluid film. By arranging the deep grooves and shallow grooves of different thicknesses to cross each other and arranging the relatively shallow grooves in a predetermined manner, it is possible to form a stable oil film regardless of the sliding speed and the magnitude of the load. It was made feasible. That is, by arranging a plurality of shallow grooves provided in one of the planes that slide relative to each other in parallel with periodicity, and arranging the plurality of shallow grooves arranged in parallel so as to intersect with the deep grooves. The fluctuation range of the thickness of the lubricating fluid film formed between the sliding planes is reduced, and the fluctuation range of the friction coefficient is reduced by stabilizing the film thickness. This is considered due to the following actions. That is, by arranging a plurality of shallow grooves so as to intersect one deep groove as described above, when the film thickness is relatively large, the hydraulic pressure rises due to the shallow grooves (dynamic pressure effect). Hardly occurs, and the presence of the shallow groove reduces the dynamic pressure effect caused by the deep groove, and thus acts in the direction of reducing the film thickness. In addition, since the plurality of shallow grooves arranged in parallel with periodicity are arranged in a direction parallel to the sliding direction or inclined at an acute angle, mainly when the thickness of the fluid film that can be formed is relatively small, The lubricating fluid flows in along the longitudinal direction of the shallow groove, and a large dynamic pressure effect is generated at the end portion on the anti-deep groove side. The dynamic pressure effect is greater when the groove depth is closer to the oil film thickness, and is maximized when the groove depth is the same. Therefore, when the oil film thickness is small, a highly rigid fluid film can be formed by the shallow groove. As a result, it is considered that the fluctuation range of the film thickness of the lubricating fluid becomes small.

Further, the deep groove may extend to an end portion of one plane where the deep groove is formed. With this configuration, since the deep groove is opened at the end of one plane, it is possible to prevent the generation of negative pressure in the deep groove region and to form a stable fluid film.

  Here, regarding the arrangement mode of the deep groove and the shallow groove, for example, the deep groove may be arranged in a direction orthogonal to the sliding direction of the other opposite plane. By comprising in this way, lubricating fluid can be supplied to a deep groove and all the shallow grooves which cross | intersect a deep groove without leak and without bias.

In addition, the plurality of shallow grooves may intersect at a direction perpendicular to the deep groove at one end . In particular, when the deep grooves are arranged in the direction perpendicular to the relative sliding direction between the opposing planes as described above, the shallow grooves are all arranged parallel to the sliding direction. The dynamic pressure effect by the shallow groove can be obtained effectively. Further, in this case, the length of the shallow groove can be made the same, so that the end of the shallow groove arranged in parallel on the side opposite to the deep groove (the other end) can be aligned. A uniform dynamic pressure effect can be generated in the width direction of the plane (direction orthogonal to the sliding direction), and a lubricating fluid film having a uniform thickness can be formed.

  The plurality of shallow grooves may be disposed on both sides of the deep groove. By configuring in this way, for example, when reciprocating sliding in the direction in which the opposite other plane intersects the deep groove, a plurality of shallow grooves arranged on one side of the deep groove with respect to one sliding direction A plurality of shallow grooves arranged on the other side of the deep groove function in the other sliding direction. Thus, the present invention can be applied to a linear motion guide mechanism that performs reciprocal motion and a thrust bearing that rotates both forward and backward. Moreover, if the shallow groove and the deep groove are arranged in combination as in the present invention, a sufficient groove length is secured to exert the required dynamic pressure effect even if the width dimension of the shallow groove is set small. Therefore, there is no particular problem in arranging a large number of shallow grooves in parallel on both sides of the deep groove.

  The plurality of shallow grooves may be formed at a pitch of 10 μm or less. By comprising in this way, the side leakage of lubricating fluid can be made harder to occur, and the effect of generating dynamic pressure can be further enhanced. As a result, the pressure drop on the side can be reduced and the rolling error can be reduced.

  Alternatively, the shallow groove may be formed to a depth of 1 μm or less. As can be seen from the experimental results to be described later, a sliding region in which the film thickness is particularly 1 μm or less is formed by forming the shallow groove in a size smaller than the order of a general dynamic pressure groove (several μm to several tens μm). Can exhibit a high dynamic pressure effect and form a highly rigid fluid film.

  Regarding the planar sliding mechanism according to the above configuration, for example, the plurality of shallow grooves irradiate one plane with a linearly polarized laser beam with an irradiation intensity in the vicinity of the processing threshold, and perform scanning while overlapping the irradiated portions. It may be formed automatically. Details are given in Japanese Patent Publication No. 4054330. According to this type of so-called laser-based self-organized parallel groove forming method, both pitch and groove depth of the order of 1 μm or less, which are difficult to machine, are obtained. The shallow groove group can be easily formed.

  As described above, according to the present invention, it is possible to provide a flat sliding mechanism that is small in oil film thickness variation and excellent in oil film rigidity regardless of the sliding speed and the load. Further, the present invention can be suitably applied not only to a thrust bearing that requires high rigidity but also to a guide mechanism of a machine tool in which a variation in oil film thickness is directly linked to machining accuracy.

It is a principal part top view of the plane sliding mechanism which concerns on one Embodiment of this invention. It is AA sectional drawing of the plane sliding mechanism shown in FIG. 1, Comprising: It is sectional drawing which shows notionally the sliding state in case an oil film thickness is comparatively large. It is AA sectional drawing of the plane sliding mechanism shown in FIG. 1, Comprising: It is sectional drawing which shows notionally the sliding state in case an oil film thickness is comparatively small. It is a principal part top view of the plane sliding mechanism which concerns on other embodiment of this invention. It is a principal part top view of the plane sliding mechanism which concerns on other embodiment of this invention. It is a figure which shows the result of a sliding experiment, Comprising: It is a figure which shows the relationship between the sliding speed and dynamic friction coefficient of the plane sliding mechanism which concerns on a comparative example. It is a figure which shows the result of a sliding experiment, Comprising: It is a figure which shows the relationship between the sliding speed and dynamic friction coefficient of the plane sliding mechanism which concerns on a comparative example. It is a figure which shows the result of a sliding experiment, Comprising: It is a figure which shows the relationship between the sliding speed and dynamic friction coefficient of the plane sliding mechanism which concerns on an Example. It is a figure which shows the result of a sliding experiment, Comprising: It is a figure which shows the relationship between the sliding speed and oil film thickness of the plane sliding mechanism which concerns on a comparative example. It is a figure which shows the result of a sliding experiment, Comprising: It is a figure which shows the relationship between the sliding speed and oil film thickness of the plane sliding mechanism which concerns on an Example. It is a figure which shows the result of a sliding experiment, Comprising: It is a figure which shows the relationship between the load and average oil film thickness in the case of varying the sliding speed of the plane sliding mechanism which concerns on a comparative example. It is a figure which shows the result of a sliding experiment, Comprising: It is a figure which shows the relationship between the load and average oil film thickness in the case of varying the sliding speed of the plane sliding mechanism which concerns on an Example.

  Hereinafter, an embodiment of a plane sliding mechanism according to the present invention will be described with reference to FIGS.

  FIG. 1: has shown the principal part top view of the plane sliding mechanism 1 which concerns on one Embodiment of this invention. Moreover, FIG. 2 has shown AA sectional drawing of the plane sliding mechanism 1 shown in FIG. As can be seen from these drawings, a deep groove 3 and a plurality of shallow grooves 4 which will be described later are formed on the one flat surface 2 constituting the flat sliding mechanism 1 at predetermined intervals along the longitudinal direction thereof.

  Here, as shown in FIG. 2, a deep groove 3 for supplying a lubricating fluid (here, for example, lubricating oil) is formed in one plane 2 between the opposing planes 2 and 5. As shown in FIGS. 1 and 2, a plurality of shallow grooves 4, 4... Shallower than the deep groove 3 and narrower in width are formed. The plurality of shallow grooves 4, 4... Are formed in parallel with periodicity, and any shallow groove 4 intersects the adjacent deep groove 3. In this embodiment, the plurality of shallow grooves 4 are all arranged in a direction intersecting with the deep grooves 3 at a predetermined angle, and each shallow groove 4 is connected to one edge of the deep groove 3 at the end thereof (FIG. 2). See).

  Looking at the planar arrangement relationship between the deep grooves 3 and the shallow grooves 4, in this embodiment, the deep grooves 3 are arranged in a direction perpendicular to the sliding direction of the other flat surface 5 (having the mating member 6). The both ends are open to the end portions on both sides of one plane 2. Therefore, the inside of the deep groove 3 is in a state where it can communicate with the outside air.

  The plurality of shallow grooves 4, 4... Have a linear shape in this embodiment, and are arranged in a lattice pattern at a predetermined pitch. Each of the shallow grooves 4, 4... Is arranged in a direction orthogonal to the deep groove 3, and in this case, as a result, parallel to the sliding direction of the other flat surface 5 (the mating member 6). Further, all the shallow grooves 4, 4... Arranged on both sides of the deep groove 3 arranged as described above are formed in the same longitudinal dimension, and the end opposite to the deep groove 3 is one plane. 2 are arranged in a line in the width direction.

  Next, looking at the dimensional relationship between the deep groove 3 and the shallow groove 4, the groove depth Wa of the deep groove 3 is not particularly limited as long as lubricating oil can be supplied between the two opposing planes 2, 5. As for the relationship with the groove depth Wb, Wa> Wb is always established. Further, the deep groove 3 is formed so that a dynamic pressure effect of the lubricating oil sufficient to form an oil film can be generated between at least one of the planes 2 where the deep groove 3 is not formed and the other plane 5 opposed to this region. It is also possible to determine the dimensions. For example, it is preferable to determine the dimensions in consideration of the weight (support load) of the mating member 6 and the sliding speed. Specifically, the groove depth Wa of the deep groove 3 is preferably set to 1 μm or more and 100 μm or less, and more preferably set to 2 μm or more and 10 μm or less. When the deep groove 3 is disposed in the direction shown in FIG. 1, the ratio of the groove width to the groove depth Wa is preferably 10 or more and 100 or less, more preferably 20 or more and 50 or less. It is good to set.

  The groove depth Wb of the shallow groove 4 is set to be smaller than the groove depth Wa of the deep groove 3 as described above. Specifically, the ratio of the groove depth Wa of the deep groove 3 to the shallow groove 4 groove depth Wb is 5 or more and 200 or less, more preferably 10 or more and 100 or less, and still more preferably 20 or more and 50. It is set to be as follows. From the viewpoint of forming a highly rigid oil film by the shallow groove 4 when the oil film thickness is small, the groove depth Wb is set to 1 μm or less, preferably 500 nm or less. The pitch between the plurality of shallow grooves 4, 4... Arranged in parallel is not particularly limited, but is appropriate in consideration of the groove depth, width dimension, longitudinal dimension, etc. of the formed shallow grooves 4, 4. A large size (for example, 10 μm or less) is set. The dimensions of the shallow groove 4, especially the groove depth Wb, can be defined in relation to the roughness or flatness of one plane 2 on which the shallow grooves 4, 4,... Are formed. It is also possible to set the surface accuracy of the flat surface 2 and the groove depth Wb of the shallow groove 4 so that the surface roughness Ra or flatness thereof does not exceed the value of the groove depth Wb. This is to secure an oil film.

  As the shallow groove 4, known groove forming means can be adopted. Further, the means for forming the plurality of shallow grooves 4, 4... Is not particularly limited. However, when forming a groove having a groove depth of 1 μm or less as described above, the irradiation intensity is, for example, near the processing threshold Effective is a means of forming a self-organized structure by irradiating a linearly polarized laser beam on one plane and scanning while overlapping the irradiated portions. According to this means, it is possible to form a plurality of shallow grooves 4, 4.

Next, the operation of the plane sliding mechanism 1 having the above configuration will be described. First, as shown in FIG.
When the sliding speed of the other opposing flat surface 5 (the mating member 6) is high or when the load from the mating member 6 is small, both the opposing flat surfaces 2 are mainly supplied by supplying lubricating oil from the deep groove 3. An oil film having a relatively large film thickness is formed between the five. In terms of the relationship with the groove depths Wa and Wb, an oil film having an oil film thickness Wc that is relatively closer to the groove depth Wa of the deep groove 3 than the groove depth Wb of the shallow groove 4 is formed. In this case, the hydraulic pressure rises at the edge portion on the front side in the sliding direction of the deep groove 3 (left edge portion in FIG. 2). In this case, the presence of the shallow grooves 4, 4... Connected to the deep groove 3 on the front side in the sliding direction widens the distance between the edge portion on the front side in the sliding direction of the deep groove 3 and the flat surface 5. It acts to reduce the dynamic pressure effect of the deep groove 3 and to suppress the rapid increase in oil film thickness.

  As shown in FIG. 3, when the sliding speed of the other plane 5 is low, or when the load from the mating member 6 is large, the flow of the lubricating oil from the deep groove 3 to the shallow groove 4 causes the shallow groove 4 to flow. A large dynamic pressure effect exceeding the dynamic pressure effect of the deep groove 3 is produced at the end portion on the side away from the deep groove 3. Due to the dynamic pressure effect of the shallow groove 4 mainly, a highly rigid oil film having a relatively small film thickness is formed between the opposing planes 2 and 5. In terms of the relationship with the groove depths Wa and Wb, an oil film having an oil film thickness Wc that is relatively closer to the groove depth Wb of the shallow groove 4 than the groove depth Wa of the deep groove 3 is formed.

  Further, the shape (dimensions) of the deep grooves 3 and the plurality of shallow grooves 4, 4... And the arrangement manner thereof are set so that the dynamic pressure effect by the deep grooves 3 and the plurality of shallow grooves 4, 4,. Thus, when the oil film is relatively thick, the fluctuation of the oil film thickness is suppressed, in other words, the fluctuation of the flying height of the counterpart member 6 is suppressed, and high positional accuracy (parallelism, etc.) is achieved with respect to the other plane 5. It can be demonstrated. Further, when the oil film is relatively thin, high oil film rigidity can be exhibited while maintaining a required positional accuracy with respect to the other flat surface 5.

  As mentioned above, although one embodiment of the present invention was described, the present invention is not limited to the above exemplary form, and it is needless to say that any form can be adopted within the scope of the present invention.

  For example, in the above embodiment, a case has been described where a plurality of shallow grooves 4, 4... Intersecting with the deep groove 3 at a predetermined angle are arranged in a direction in which the longitudinal direction is parallel to the sliding direction of the other plane 5. Of course, it is possible to arrange them in other directions. FIG. 4 shows an example thereof. A plurality of shallow grooves 4, 4... Connected at the deep groove 3 and its end are inclined at a predetermined angle with respect to the sliding direction of the other plane 5. The case where it arrange | positions is shown in figure. Thus, the shallow groove 4 can take any angle as long as it is parallel to the sliding direction or inclined at an inclination angle of less than 90 °, in other words, as long as it is not orthogonal to the sliding direction. Further, it is not necessary that all the shallow grooves 4, 4... Connected to the deep groove 3 are aligned in the same direction, and the shallow groove 4 is inclined on one side and the other side of the deep groove 3 as shown in FIG. The angles may be different, and the inclination angles may be different between the adjacent shallow grooves 4 and 4.

  Also, the longitudinal dimensions of the shallow grooves 4 do not necessarily have to be the same for all the shallow grooves 4, 4..., And may be appropriately varied according to the arrangement mode. FIG. 5 shows an example. In the plane sliding mechanism 1 shown in FIG. 5, a plurality of shallow grooves 4, 4... Are arranged on one plane 2 in parallel with the sliding direction. The longitudinal dimensions of the respective shallow grooves 4 are set so that the end portions on the side away from the deep grooves 3 that are hydraulic rising portions are aligned in a line in the width direction.

  Also, the arrangement of the deep grooves 3 is not particularly limited, and for example, as shown in FIGS. 2 and 4, they can be arranged in a direction orthogonal to the sliding direction, or as shown in FIG. Further, it can be arranged in a direction intersecting with the sliding direction at a predetermined angle (acute angle).

  Of course, the shape of the deep groove 3 and the shallow groove 4 need not be limited to the illustrated embodiment. For example, although illustration is omitted, the deep groove 3 is V-shaped and lubricating oil is injected into the deep groove 3 from the side of the plane 2. The deep grooves 3 and the shallow grooves 4 may be formed by an arbitrary combination of one or more straight lines or curves so as to facilitate supply.

  Of course, other specific forms can be adopted for matters other than the above as long as the technical significance of the present invention is not lost.

  Hereinafter, an experiment for verifying the effectiveness of the planar sliding mechanism according to the present invention will be described.

  This experiment was conducted using a ring-on-disk test apparatus that can easily realize parallel sliding in order to prevent changes in lubrication characteristics due to the inclination of the test piece. A hardened material of SUS440C was used for the ring-shaped test piece on the rotating side. SiC was used for the disk-shaped test piece on the fixed side. The sliding plane of any test piece was set to have a surface roughness Ra of 0.02 μm or less and a flatness of 0.1 μm or less. All sliding planes of the disk-shaped test piece were mirror surfaces. Three types of ring-shaped test pieces (outer diameter: 16 mm, inner diameter: 10 mm) were prepared: (1) mirror surface, (2) deep groove only, and (3) combination of deep groove and shallow groove. (1) and (2) are comparative examples, and (3) is an example. The deep grooves were arranged in a direction extending in the radial direction of the ring-shaped plane, in other words, in a direction perpendicular to the sliding direction of the mating member (disk). Eight of these deep grooves were arranged at equal intervals in the circumferential direction. The width of the deep groove was 200 μm and the groove depth was 6 μm. The shallow grooves were arranged in parallel in a lattice pattern at a pitch of about 700 nm on both side edges of the deep grooves. The longitudinal dimension was set (about 400 μm) so that the shallow groove was disposed in a region having a width of 1 mm with the deep groove as the center. The depth of the shallow groove was 200 nm, and the arrangement direction was perpendicular to the deep groove. The plurality of shallow grooves are irradiated with a femtosecond laser having a wavelength of 800 nm and linearly polarized light on the sliding plane of the test piece with an irradiation intensity in the vicinity of the processing threshold, and scanning is performed while overlapping the irradiated portions. Formed. 400 mg of lubricating oil (viscosity grade: VG32) was previously supplied onto the sliding plane, and no oil was supplied during the experiment.

  In the ring-on-disk test, the load is fixed at a predetermined value, and after starting from a stationary state at a sliding speed of 1.2 m / s, the sliding speed is gradually reduced to 0.14 m / s every 5 minutes. The sliding torque at each stage was measured. The sliding speed was a value at the average diameter (13 mm) of the ring-shaped test piece. The dynamic friction coefficient was calculated from the measured sliding torque. The load was set in five stages of 9.0N, 19.3N, 30.0N, 40.8N, and 50.5N. The above test was performed on all three types of test pieces: (1) mirror surface, (2) deep groove only, and (3) combination of deep groove and shallow groove.

The experimental results are described below. FIG. 6 shows the results of a sliding experiment when the sliding plane is a mirror surface (comparative example), where the horizontal axis is the sliding time [min], the left vertical axis is the dynamic friction coefficient, and the right vertical axis is the sliding. The velocity [m / s] is shown respectively. A portion indicated by a broken line in the figure indicates a sliding speed, and a portion indicated by a solid line indicates a dynamic friction coefficient. FIG. 7 shows the result of a sliding experiment when the sliding plane is composed only of deep grooves (comparative example), and FIG. 8 shows the case where the sliding plane is a combination of deep and shallow grooves ( The result of the sliding experiment of Example) is shown. Items on the horizontal axis and both vertical axes, and items indicated by various lines in the figure are the same as those in FIG. First, from the experimental results shown in FIG. 6, (1) on the mirror surface, a rapid increase in the coefficient of dynamic friction was observed at a predetermined sliding speed (0.54 m / s). On the other hand, as shown in FIGS. 7 and 8, in the case of (2) only the deep groove and (3) the combination of the deep groove and the shallow groove, it is observed that the dynamic friction coefficient is low throughout all the measured sliding speed stages. It was. It is considered that this was in a fluid lubrication state regardless of the sliding speed. Here, when FIG. 7 and FIG. 8 are viewed in detail, (2) In the case of only the deep groove, (1) The dynamic friction coefficient is generally lower than that in the case of the mirror surface , but the fluctuation range is large in the entire sliding velocity region, There was a point of lack of stability. In contrast, (3) in the case of a combination of deep grooves and shallow grooves, the coefficient of dynamic friction is generally higher than in the case of (2) only deep grooves, but the fluctuation range is small, and stable oil film support can be seen. It was.

  FIGS. 9 and 10 are both obtained from the experimental results shown in FIGS. 7 and 8, and FIG. 9 shows the change in the oil film thickness accompanying the change in the sliding speed when only the deep groove (comparative example) is used. . FIG. 10 shows the change in the oil film thickness accompanying the change in the sliding speed in the case of the combination of the deep groove and the shallow groove (example). Here, in both FIGS. 9 and 10, the left vertical axis represents the oil film thickness [μm], and the right vertical axis represents the sliding speed [m / s]. In the figure, the part indicated by the broken line indicates the sliding speed, and the part indicated by the solid line indicates the oil film thickness. The oil film thickness was calculated from the dynamic friction coefficient obtained in the previous sliding experiment and the viscosity of the used lubricating oil (this time, the viscosity value at room temperature was used). From the experimental results shown in FIG. 9 and FIG. 10, although the combination of deep grooves and shallow grooves has a smaller oil film thickness as a whole, the fluctuation range is smaller than in the case of only deep grooves, and a stable oil film is formed. I understand that it was. In addition, when the standard deviation of each oil film thickness was taken, it was found that the standard deviation was reduced by about a half in the case of a combination of deep grooves and shallow grooves compared to the case of only deep grooves.

  11 and 12 both calculate the average oil film thickness in each sliding speed region from the measurement result of the dynamic friction coefficient at the set load at each stage. FIG. 11 shows the load and average when only the deep groove (comparative example) is shown in FIG. FIG. 12 shows the relationship between the oil film thickness and the relationship between the load and the average oil film thickness in the case of the combination of the deep groove and the shallow groove (example). 11 and 12, the horizontal axis represents the load [N], and the vertical axis represents the average oil film thickness [μm]. Moreover, the plot shown by the rhombus in the figure shows the average oil film thickness when the sliding speed is 1.09 m / s. Similarly, the plot shown by the square in the figure is a sliding speed of 0.54 m / s and is shown by a triangle in the figure. The plots shown indicate the average oil film thickness when the sliding speed is 0.35 m / s, and the plots indicated by penalty points in the figure indicate the sliding speed of 0.14 m / s. Here, from the experimental results shown in FIG. 11, in the case of only deep grooves, the variation in average oil film thickness when the sliding speed fluctuates in a low load region (here, a region surrounded by an ellipse drawn on the left in FIG. 11). It can be seen that the width is large. On the other hand, from the experimental results shown in FIG. 12, in the case of a combination of deep grooves and shallow grooves, the fluctuation range of the average oil film thickness is small in the low load region even if the sliding speed varies. Further, in the high load region (here, the region surrounded by an ellipse drawn by the solid line on the right side in FIG. 11), in the case of only the deep groove, the degree of decrease in the average oil film thickness accompanying the increase in load is relatively large. In the case of a combination of deep grooves and shallow grooves, it can be seen that the average oil film thickness does not decrease as much as the load increases. From this, it can be considered that the planar sliding mechanism according to the combination of the deep groove and the shallow groove exhibits high rigidity particularly at high load. Also, when a predetermined load (40 N) is exceeded in the high load region, the size of the oil film thickness that can be formed between the comparative example and the example is reversed during both high speed sliding and low speed sliding (the oil film thickness of the example). Was higher than that of the comparative example).

DESCRIPTION OF SYMBOLS 1 Plane sliding mechanism 2 (One) plane 3 Deep groove 4 Shallow groove 5 (Other) plane 6 Mating member Wa Groove depth (deep groove)
Wb groove depth (shallow groove)
Wc Oil film thickness

Claims (8)

A plane sliding mechanism for performing relative sliding between opposing planes via a film of lubricating fluid, wherein either one of the planes includes a deep groove for supplying the lubricating fluid between the opposing planes. And a shallow groove shallower than the deep groove,
The shallow grooves are arranged in parallel with periodicity,
Arranged in parallel said plurality of shallow grooves are in Ri Contact rises toward the plane of said one in the deep grooves and Majiwa Rutotomoni other end at one end and to the sliding direction opposing said other plane A plane sliding mechanism arranged in parallel or at an inclination angle of less than 90 °. The deep groove is planar sliding mechanism according to claim 1 which extends to the end of the one plane.   The plane sliding mechanism according to claim 1 or 2, wherein the deep groove is arranged in a direction orthogonal to the sliding direction of the other plane. The planar sliding mechanism according to any one of claims 1 to 3, wherein the plurality of shallow grooves intersect in a direction orthogonal to the deep groove at one end .   The planar sliding mechanism according to claim 1, wherein the plurality of shallow grooves are disposed on both sides of the deep groove.   The planar sliding mechanism according to claim 1, wherein the plurality of shallow grooves are formed at a pitch of 10 μm or less.   The planar sliding mechanism according to claim 1, wherein the shallow groove is formed to a depth of 1 μm or less.   The plurality of shallow grooves are formed in a self-organized manner by irradiating the one plane with a linearly polarized laser beam with an irradiation intensity in the vicinity of a processing threshold, and scanning while overlapping the irradiated portions. Item 8. A planar sliding mechanism according to any one of Items 1 to 7.