A piston cylinder having a common micro-textured surface

Abstract

The application discloses a piston cylinder with a common micro-textured surface, comprising a cylinder liner and a piston, characterized in that the inner wall of the cylinder liner is divided into five areas along the axial direction of the cylinder liner, which are boundary lubrication area, mixed lubrication area, fluid lubrication area, mixed lubrication area and boundary lubrication area in sequence, and the surfaces of the five areas are provided with surface micro-texture; and the surface of the piston ring in contact with the inner wall of the cylinder liner is provided with surface micro-texture. The application divides the inner wall of the cylinder liner into five areas, sets different micro-textured surfaces and friction coefficients, and the different micro-textured surfaces have different effects, so that the periodic changes of the internal pressure of the cylinder liner and the speed of the piston ring can be met, and the friction coefficients of the different micro-textured surfaces can meet the demand of the lubrication and friction performance of each area of the surface of the cylinder liner.

Description

Technical Field

[0001] This invention belongs to the field of microtexture friction reduction, and specifically relates to a piston cylinder with a common microtexture surface. Background Technology

[0002] During the operation of a piston cylinder, the cylinder liner and piston rings are the most important friction pair within the cylinder, playing irreplaceable roles in sealing and lubrication. However, the friction loss generated by this pair during operation accounts for approximately 26% of the total friction loss of the piston cylinder, and its performance affects the lifespan and stability of the piston cylinder.

[0003] Surface microtexturing, as a surface modification technology, utilizes physical and chemical methods to process regularly ordered arrays of tiny structures on the surface of materials. Microtexturing, as a friction-reducing method, has already been applied in various fields such as engine components, cutting tools, computer hard drives, and underwater vehicles. Currently, surface microtexturing is being used to improve the friction and wear of cylinder liners and piston rings.

[0004] Most existing inventions and designs for reducing friction and wear resistance in cylinder liner-piston ring systems focus on reducing friction through microtextures on a single surface. Few consider the different stages of friction that the cylinder liner-piston ring system experiences. Furthermore, designs that combine the microtextures of the cylinder liner and piston ring surfaces and apply them to the piston ring-cylinder liner moving pair are relatively rare. Summary of the Invention

[0005] The purpose of this invention is to provide a piston cylinder with a common microtextured surface, so as to solve the technical problem of using only a single surface microtexturation in the prior art.

[0006] The present invention provides a piston cylinder with a common microtextured surface, comprising: a cylinder liner and a piston; the inner wall of the cylinder liner is divided into five regions along the cylinder liner axis, namely: a boundary lubrication region, a mixed lubrication region, a fluid lubrication region, a mixed lubrication region, and a boundary lubrication region, and the surface of each of the five regions is provided with a surface microtexture; the piston ring of the piston is provided with a surface microtexture on the side that contacts the inner wall of the cylinder liner.

[0007] Furthermore, the friction coefficient of the surface microtexture in the boundary lubrication region ranges from 0.055 to 0.080; the friction coefficient of the surface microtexture in the mixed lubrication region ranges from 0.045 to 0.055; and the friction coefficient of the surface microtexture in the fluid lubrication region ranges from 0.003 to 0.045.

[0008] Furthermore, the division ratio of the five regions is: 1.68:3.52:91.68:2:1.12.

[0009] Furthermore, the surface microtexture of the boundary lubrication region includes: several sinusoidal wave-filled groove microtextures, which are evenly distributed along the cylinder liner axial direction, and one sinusoidal wave-filled groove microtexture encircles the inner wall of the cylinder liner once; the surface microtexture of the mixed lubrication region includes: several sinusoidal wave-filled groove microtextures and several circular pit microtextures, which are evenly distributed along the cylinder liner axial direction, one sinusoidal wave-filled groove microtexture encircles the inner wall of the cylinder liner once, and several circular pit microtextures arranged in an array with staggered spacing, with one circular pit in a row... The pit microtexture is located in the crest of the sinusoidal wave-filled groove microtexture and is coaxial with the crest. The circular pit microtexture in an adjacent misaligned row is located in the trough of the sinusoidal wave-filled groove microtexture and is coaxial with the trough. The surface microtexture of the fluid lubrication area includes: several polygonal pit microtextures or several circular pit microtextures, which are arranged in an array. The surface microtexture on the piston ring includes: several polygonal pit microtextures or several circular pit microtextures, which are arranged in an array.

[0010] Furthermore, the width of the sinusoidal wave-filled groove microtexture in the boundary lubrication region ranges from 0.19 mm to 0.22 mm; the period of one sinusoidal wave-filled groove microtexture ranges from 1.8 mm to 2.1 mm; the spacing between adjacent sinusoidal wave-filled groove microtextures ranges from 1.4 mm to 1.6 mm; and the groove depth of the sinusoidal wave-filled groove microtexture ranges from 0.03 mm to 0.05 mm.

[0011] Furthermore, the width of the sinusoidal wave-filled groove microtexture in the mixed lubrication region ranges from 0.13 mm to 0.16 mm; one period of the sinusoidal wave-filled groove microtexture ranges from 1.8 mm to 2.1 mm; the spacing between adjacent sinusoidal wave-filled groove microtextures ranges from 1.4 mm to 1.6 mm; and the groove depth of the sinusoidal wave-filled groove microtexture ranges from 0.03 mm to 0.05 mm.

[0012] The radius of the circular pit microtexture ranges from 0.14 mm to 0.16 mm; the depth of the circular pit microtexture ranges from 0.05 mm to 0.07 mm; the spacing between the circular pit microtexture and the sinusoidal wave-filled groove microtexture ranges from 0.18 mm to 0.22 mm; the lateral misalignment range of the arrayed staggered circular pit microtexture is 0.9 mm to 1.1 mm, the longitudinal misalignment range is 0.4 mm to 0.6 mm, the row spacing range is 1.4 mm to 1.5 mm, and the column spacing range is 1.9 mm to 2.1 mm.

[0013] Furthermore, the radius of the microtexture in the fluid lubrication region ranges from 0.13 mm to 0.16 mm; the depth of the microtexture ranges from 0.04 mm to 0.06 mm; the row spacing of the microtexture ranges from 1.3 mm to 1.6 mm; and the column spacing ranges from 1.3 mm to 1.6 mm.

[0014] Furthermore, the radius of the circular pit microtexture on the piston ring ranges from 0.09 mm to 0.11 mm; the groove depth of the circular pit microtexture ranges from 0.07 mm to 0.09 mm; the row spacing of the circular pit microtexture ranges from 0.2 mm to 0.4 mm, and the column spacing ranges from 0.2 mm to 0.4 mm.

[0015] Furthermore, the filler in the sinusoidal wave filled groove microtexture is molybdenum disulfide.

[0016] Furthermore, the surface microtextures are all formed by laser ablation.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention divides the inner wall of the cylinder liner into five regions, and sets different micro-textured surfaces and friction coefficients. Different micro-textured surfaces will have different effects, which can meet the periodic changes in internal pressure and piston ring speed of the cylinder liner. Different micro-textured surface friction coefficients can meet the lubrication and friction performance requirements of each region of the cylinder liner surface.

[0019] This invention sets five regional division ratios to effectively divide the friction areas on the cylinder liner surface, which can adapt to the division of various cylinder liner surfaces, so as to achieve the effect that the cylinder liner is not limited to the working stroke length.

[0020] This invention employs different forms of common microtextured surfaces. Compared with single-surface microtextures, common microtextures can combine the effects of piston ring surface microtextures and cylinder liner surface microtexture grooves. The coupling effect of common microtextures provides the surface with the best oil film thickness and the highest debris capture efficiency, improving the running-in quality, load-bearing capacity, and oil storage capacity between the cylinder liner and piston rings, ultimately achieving better friction reduction. Attached Figure Description

[0021] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0022] Figure 1 This is a cross-sectional schematic diagram of the piston cylinder in a specific embodiment of the present invention;

[0023] Figure 2 This is a cross-sectional view of the cylinder liner in a specific embodiment of the present invention;

[0024] Figure 3 This is a front view of the piston in a specific embodiment of the present invention;

[0025] Figure 4 This is a graph showing the variation of the average friction coefficient with the position near the top dead center of the cylinder liner in a specific embodiment of the present invention.

[0026] Figure 5 This is a graph showing the variation of the average friction coefficient with the position near the bottom dead center of the cylinder liner in a specific embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of cylinder liner surface division based on friction coefficient in a specific embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the surface microtexture of the boundary lubrication region in a specific embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the surface microtexture of the mixed lubrication region in a specific embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram of the surface microtexture of the fluid lubrication region in a specific embodiment of the present invention;

[0031] Figure 10 This is a schematic diagram of the microtexture on the piston ring surface in a specific embodiment of the present invention. Detailed Implementation

[0032] The present invention will be further described in detail below through specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the art according to the specification. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. In the description of the present invention, it should be understood that the terms "surface," etc., indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0033] like Figure 1-3As shown, a specific embodiment of the present invention provides a piston cylinder with a common microtextured surface, including: a cylinder liner and a piston; the inner wall of the cylinder liner is divided into five regions along the cylinder liner axis, namely: boundary lubrication region 1, mixed lubrication region 2, fluid lubrication region 3, mixed lubrication region 2, and boundary lubrication region 1, and the surfaces of the five regions are provided with surface microtexture; the piston ring of the piston is provided with surface microtexture 4 on the side that contacts the inner wall of the cylinder liner.

[0034] When the piston passes through these five regions, the friction coefficients are different. The friction coefficient of the surface microtexture in the boundary lubrication region ranges from 0.055 to 0.08; the friction coefficient of the surface microtexture in the mixed lubrication region ranges from 0.045 to 0.055; and the friction coefficient of the surface microtexture in the fluid lubrication region ranges from 0.003 to 0.045.

[0035] The five-segment division ratio is 1.68:3.52:91.68:2:1.12. Taking the YTRC2110D diesel engine as an example, its piston cylinder height is 125mm. Dividing each segment according to the above ratio, they are: a boundary lubrication zone with a height of 2.1mm, a mixed lubrication zone with a height of 4.4mm, a fluid lubrication zone with a height of 114.6mm, a mixed lubrication zone with a height of 2.5mm, and a boundary lubrication zone with a height of 1.4mm. The two boundary lubrication zones account for 2.8% of the cylinder liner inner wall area; the two mixed lubrication zones account for 5.52% of the cylinder liner inner wall area; and the fluid lubrication zone accounts for 91.68% of the cylinder liner inner wall area.

[0036] like Figure 7-10 As shown, the surface microtexture of the boundary lubrication region includes: several sinusoidal wave-filled groove microtextures, which are evenly distributed along the cylinder liner axial direction, and one sinusoidal wave-filled groove microtexture encircles the inner wall of the cylinder liner once; the surface microtexture of the mixed lubrication region includes: several sinusoidal wave-filled groove microtextures and several circular pit microtextures, which are evenly distributed along the cylinder liner axial direction, one sinusoidal wave-filled groove microtexture encircles the inner wall of the cylinder liner once, and several circular pit microtextures arranged in an array with staggered spacing, with one circular pit microtexture in a row... The texture is located in the crest of the sinusoidal wave-filled groove microtexture and is coaxial with the crest. The circular pit microtexture in an adjacent misaligned row is located in the trough of the sinusoidal wave-filled groove microtexture and is coaxial with the trough. The surface microtexture of the fluid lubrication area includes: several polygonal pit microtextures or several circular pit microtextures, and the several polygonal pit microtextures or several circular pit microtextures are arranged in an array. The surface microtexture on the piston ring includes: several polygonal pit microtextures or several circular pit microtextures, and the several polygonal pit microtextures or several circular pit microtextures are arranged in an array.

[0037] Surface microtextures on cylinder liners and pistons: sinusoidal wave filled groove microtextures, circular pit microtextures, and polygonal pit microtextures are all formed by laser ablation. Among them, molybdenum disulfide is preferred as the filler in the sinusoidal wave filled groove microtexture. Of course, other fillers that help lubrication can replace molybdenum disulfide as the filler in the sinusoidal wave filled groove microtexture.

[0038] The width b1 of the sinusoidal wave-filled groove microtexture in the boundary lubrication region ranges from 0.19 mm to 0.22 mm; the period e1 of one sinusoidal wave-filled groove microtexture ranges from 1.8 mm to 2.1 mm; the spacing c1 between adjacent sinusoidal wave-filled groove microtextures ranges from 1.4 mm to 1.6 mm; and the groove depth of the sinusoidal wave-filled groove microtexture ranges from 0.03 mm to 0.05 mm.

[0039] The width b2 of the sinusoidal wave-filled groove microtexture in the mixed lubrication region ranges from 0.13 mm to 0.16 mm; the period e2 of one sinusoidal wave-filled groove microtexture ranges from 1.8 mm to 2.1 mm; the spacing c2 between adjacent sinusoidal wave-filled groove microtextures ranges from 1.4 mm to 1.6 mm; and the groove depth of the sinusoidal wave-filled groove microtexture ranges from 0.03 mm to 0.05 mm.

[0040] The radius R2 of the circular pit microtexture ranges from 0.14 mm to 0.16 mm; the depth of the circular pit microtexture ranges from 0.05 mm to 0.07 mm; the spacing l2 between the circular pit microtexture and the sinusoidal wave-filled groove microtexture ranges from 0.18 mm to 0.22 mm; the lateral misalignment r of the arrayed staggered circular pit microtexture... x2 The range is 0.9mm to 1.1mm, with a longitudinal misalignment r. y2 The range is 0.4mm to 0.6mm, and the line spacing t y2 The range is 1.4mm to 1.5mm, and the column spacing t is... x2 The range is 1.9mm to 2.1mm.

[0041] The radius R3 of the microtexture in the fluid lubrication region ranges from 0.13 mm to 0.16 mm; the depth of the microtexture ranges from 0.04 mm to 0.06 mm; and the row spacing t of the microtexture... y3 The range is 1.3mm to 1.6mm, and the column spacing t is... x3 The range is 1.3mm to 1.6mm.

[0042] The radius R of the circular pit microtexture on the piston ring ranges from 0.09 mm to 0.11 mm; the depth of the circular pit microtexture ranges from 0.07 mm to 0.09 mm; and the row spacing t of the circular pit microtexture... yThe range is 0.2mm to 0.4mm, and the column spacing t x The range is 0.2mm to 0.4mm.

[0043] The following is an experimental description of a specific embodiment of the present invention:

[0044] The experiment used a YTRC2110D diesel engine with a piston cylinder height of 125mm and five sections with heights of 2.1mm, 4.4mm, 114.6mm, 2.5mm, and 1.4mm respectively.

[0045] The width b1 of the sinusoidal wave-filled groove microtexture in the boundary lubrication region is 0.2 mm; the period e1 of one sinusoidal wave-filled groove microtexture is 2 mm; the spacing c1 between adjacent sinusoidal wave-filled groove microtextures is 1.5 mm; and the groove depth of the sinusoidal wave-filled groove microtexture is 0.04 mm.

[0046] The width b2 of the sinusoidal wave-filled groove microtexture in the mixed lubrication region is 0.15 mm; the period e2 of one sinusoidal wave-filled groove microtexture is 2 mm; the spacing c2 between adjacent sinusoidal wave-filled groove microtextures is 1.5 mm; and the groove depth of the sinusoidal wave-filled groove microtexture is 0.04 mm.

[0047] The radius R2 of the circular pit microtexture is 0.15 mm; the depth of the circular pit microtexture is 0.06 mm; the spacing l2 between the circular pit microtexture and the sinusoidal wave-filled groove microtexture is 0.2 mm; the lateral misalignment r of the arrayed staggered circular pit microtexture is... x2 The value is 1mm, with a longitudinal misalignment of r. y2 The line spacing is 0.5mm, and the line spacing is t. y2 The value is 1.5mm, and the column spacing is t. x2 The value is 2mm.

[0048] The radius R3 of the microtexture in the fluid lubrication region is 0.15 mm; the depth of the microtexture is 0.05 mm; and the row spacing t of the microtexture is... y3 The value is 1.5mm, and the column spacing is t. x3 The value is 1.5mm.

[0049] The radius R of the circular pit microtexture on the piston ring is 0.1 mm; the depth of the circular pit microtexture is 0.08 mm; the row spacing t of the circular pit microtexture is... y The value is 0.3mm, and the column spacing is t. x The value is 0.3mm.

[0050] like Figure 4As shown, during the process of the cylinder liner's top dead center from 0 mm to 6.9 mm, the coefficient of friction rapidly decreases from 0.153 to 0.041, and then gradually decreases to 0.032, showing a trend of first decreasing rapidly and then leveling off. According to Robert H. Thursto, the minimum coefficient of friction appears, and 6.9 mm is the turning point between the mixed lubrication state and the hydrodynamic lubrication state.

[0051] The point of minimum friction coefficient on the Stribeck curve is the transition point between fluid lubrication and mixed lubrication; the friction coefficient for hydrodynamic lubrication is 10. -2 ~10 -3 The coefficient of friction for boundary lubrication is 0.1, while that for mixed lubrication lies between boundary lubrication and fluid lubrication. Therefore, in this embodiment, the boundary lubrication area at a height of 2.1 mm and the mixed lubrication area at a height of 4.4 mm on the cylinder liner surface meet the requirements for the coefficient of friction.

[0052] like Figure 5 As shown, when the cylinder liner's bottom dead center (BDC) depth decreases from 125mm to 120.5mm, the coefficient of friction rapidly drops from 0.136 to 0.102, then slowly decreases to 0.051, exhibiting a trend of first decreasing and then stabilizing. Furthermore, when the cylinder liner position is 121.1mm, it represents the minimum average coefficient of friction near the BDC, at 0.051. Based on Robert H. Thurston's minimum coefficient of friction and Stribeck's lubrication theory, 120.5mm is determined to be the cylinder liner position with the minimum coefficient of friction, marking the transition between hydrodynamic lubrication and mixed lubrication. Therefore, in this embodiment, the division of the cylinder liner surface into a hydrodynamic lubrication region at a height of 114.6mm, a mixed lubrication region at a height of 2.5mm, and a boundary lubrication region at a height of 1.4mm meets the requirements for the coefficient of friction.

[0053] like Figure 6 As shown, the boundary lubrication area of ​​the cylinder liner surface is 0mm to 2.1mm, the mixed lubrication area is 2.1mm to 6.5mm, the fluid lubrication area is 6.5mm to 62.5mm, the mixed lubrication area is 121.1mm to 123.6mm, and the boundary lubrication area is 123.6mm to 125mm. It can be seen from the figure that the area division method first meets the requirements of the friction coefficient, and also meets the division ratio of the five areas of the cylinder liner surface as 1.68:3.52:91.68:2:1.12.

[0054] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A piston cylinder having a common micro-textured surface, comprising: Cylinder liner and piston, characterized in that the inner wall of the cylinder liner is divided into five regions along the cylinder liner axis: a boundary lubrication region, a mixed lubrication region, a fluid lubrication region, and a boundary lubrication region. Each of the five regions has a surface microtexture. Among them, the surface microtexture of the boundary lubrication area includes: several sinusoidal wave filled groove microtextures, several sinusoidal wave filled groove microtextures are distributed at equal intervals along the cylinder liner axis, and one sinusoidal wave filled groove microtexture circles around the inner wall of the cylinder liner. The surface microtexture of the mixed lubrication area includes: several sinusoidal wave-filled groove microtextures and several circular pit microtextures. The sinusoidal wave-filled groove microtextures are distributed at equal intervals along the cylinder liner axis. One sinusoidal wave-filled groove microtexture circles around the inner wall of the cylinder liner. The several circular pit microtextures form an array of staggered arrangements. The circular pit microtextures in one row are located in the crest of the sinusoidal wave-filled groove microtexture and are coaxial with the crest. The circular pit microtextures in adjacent staggered rows are located in the trough of the sinusoidal wave-filled groove microtexture and are coaxial with the trough. The surface microtexture of the fluid lubrication area includes: several polygonal pit microtextures or several circular pit microtextures, and the several polygonal pit microtextures or several circular pit microtextures are arranged in an array. The piston rings of the piston are provided with surface microtextures on the side that contacts the inner wall of the cylinder liner. The surface microtextures on the piston rings include: several polygonal pit microtextures or several circular pit microtextures, and the several polygonal pit microtextures or several circular pit microtextures are arranged in an array.

2. The piston cylinder with a common microtextured surface as described in claim 1, characterized in that, The friction coefficient of the surface microtexture in the boundary lubrication region ranges from 0.055 to 0.080; the friction coefficient of the surface microtexture in the mixed lubrication region ranges from 0.045 to 0.055; and the friction coefficient of the surface microtexture in the fluid lubrication region ranges from 0.003 to 0.

045.

3. The piston cylinder with a common microtextured surface as described in claim 1, characterized in that, The division ratio of the five regions is as follows: 1.68：3.52：91.68：2：1.12。 4. The piston cylinder with a common microtextured surface as described in claim 1, characterized in that, The width of the sinusoidal wave-filled groove microtexture in the boundary lubrication region ranges from 0.19 mm to 0.22 mm; the period of one sinusoidal wave-filled groove microtexture ranges from 1.8 mm to 2.1 mm; the spacing between adjacent sinusoidal wave-filled groove microtextures ranges from 1.4 mm to 1.6 mm; and the groove depth of the sinusoidal wave-filled groove microtexture ranges from 0.03 mm to 0.05 mm.

5. The piston cylinder with a common microtextured surface as described in claim 1, characterized in that, The width of the sinusoidal wave-filled groove microtexture in the mixed lubrication region ranges from 0.13 mm to 0.16 mm; the period of one sinusoidal wave-filled groove microtexture ranges from 1.8 mm to 2.1 mm; the spacing between adjacent sinusoidal wave-filled groove microtextures ranges from 1.4 mm to 1.6 mm; and the groove depth of the sinusoidal wave-filled groove microtexture ranges from 0.03 mm to 0.05 mm. The radius of the circular pit microtexture ranges from 0.14 mm to 0.16 mm; the depth of the circular pit microtexture ranges from 0.05 mm to 0.07 mm; the spacing between the circular pit microtexture and the sinusoidal wave-filled groove microtexture ranges from 0.18 mm to 0.22 mm; the lateral misalignment range of the arrayed staggered circular pit microtexture is 0.9 mm to 1.1 mm, the longitudinal misalignment range is 0.4 mm to 0.6 mm, the row spacing ranges from 1.4 mm to 1.5 mm, and the column spacing ranges from 1.9 mm to 2.1 mm.

6. The piston cylinder with a common microtextured surface as described in claim 1, characterized in that, The radius of the microtexture in the fluid lubrication region ranges from 0.13 mm to 0.16 mm; the depth of the pit microtexture ranges from 0.04 mm to 0.06 mm; the row spacing of the microtexture ranges from 1.3 mm to 1.6 mm; and the column spacing ranges from 1.3 mm to 1.6 mm.

7. The piston cylinder with a common microtextured surface as described in claim 1, characterized in that, The radius of the circular pit microtexture on the piston ring ranges from 0.09 mm to 0.11 mm; the depth of the circular pit microtexture ranges from 0.07 mm to 0.09 mm; the row spacing of the circular pit microtexture ranges from 0.2 mm to 0.4 mm, and the column spacing ranges from 0.2 mm to 0.4 mm.

8. The piston cylinder with a common microtextured surface as described in claim 1, characterized in that, The filler in the sinusoidal wave-filled groove microtexture is molybdenum disulfide.

9. The piston cylinder having a common microtextured surface as described in any one of claims 1-8, characterized in that, The surface microtextures are all formed by laser ablation.

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