EP3910097B1

EP3910097B1 - Ring of spinning machine and manufacturing method for the ring

Info

Publication number: EP3910097B1
Application number: EP21169592.9A
Authority: EP
Inventors: Hisaaki Hayashi; Naomichi Tominaga; Munehisa Matsui; Akihiro Shinohara
Original assignee: Toyota Industries Corp
Current assignee: Toyota Industries Corp
Priority date: 2020-05-12
Filing date: 2021-04-21
Publication date: 2023-08-09
Anticipated expiration: 2041-04-21
Also published as: CN113652784B; EP3910097A1; JP2021179032A; JP7390969B2; CN113652784A

Description

The present invention relates to a ring of a spinning machine and a manufacturing method for the ring.

BACKGROUND ART

In the spinning process for producing yarn from raw cotton, as a nearly final stage thereof, a fine spinning process is performed. In the fine spinning process, green yarn produced in the roving process is elongated to a predetermined thickness, twisted, and wound on a bobbin. The fine spinning process is performed mainly by a ring spinning machine. The ring spinning machine winds up a yarn through a traveler that glides (slides) on a ring, which is supported by a ring rail and is movable up and down.
The ring spinning machine is desirable to operate continuously for a long time at high speed in order to increase the productivity of the spinning process (particularly, the fine spinning process). For the purpose, tribological property of the ring and the traveler under non-liquid lubrication (dry state) is desirably improved or enhanced to extend the lifetime of the ring and the traveler (time for replacement). JP 2002 510755 A mentions a solution for this matter.
The above-mentioned JP 2002 510755 A proposes hard chrome plating of a sliding surface of the ring. JP 5 910 569 B2 proposes a periodic structure that has a recess and a flat surface and is formed on a sliding surface of a ring. JP 5 994 721 B1 proposes chrome plating of a sliding surface of a ring, wherein microcracks (recesses) are formed in a chrome plating layer of the sliding surface. JP 6 149 838 B2 proposes chrome plating of a sliding surface of a ring, wherein large recesses (dimples) and small recesses (microcracks) are formed in a chrome plating layer of the sliding surface. EP 3 009 542 A1 proposes forming a plurality of dimples in at least one of sliding surfaces of a ring and a traveler. GB 1 322 832 A proposes applying a film of gold to those parts of a traveler in contact with a ring.
US 3 084 501 A discloses a ring of a spinning machine as specified in the preamble of claim 1. The ring is produced by machining the base metal of the ring to roughly approximately its finished contour, during which spaced concentric grooves are formed in a sliding surface to be brought into contact with a traveler, and by electro-polishing the ring.
The present invention, which has been made in light of such circumstances, is directed to providing a ring of a spinning machine and a manufacturing method for the ring, the ring having enhanced tribological property.

SUMMARY

In accordance with an aspect of the present disclosure, there is provided a ring of a spinning machine. The spinning machine is configured to wind a yarn through a traveler. The ring has a sliding surface on which the traveler slides. The sliding surface has a texture having a plurality of recesses and a plurality of projections. Each projection has a curved shape and is located between adjacent recesses. The projection has a curvature radius of 40 to 400 µm.
In accordance with another aspect of the present disclosure, there is provided a method for manufacturing the ring of the spinning machine. The method for manufacturing the ring includes a step for forming the sliding surface. The step for forming the sliding surface includes: a first step for forming a plurality of dimples in a surface of the ring; and a second step for rounding a peripheral edge of each dimple and/or a portion between adjacent dimples.
Other aspects and advantages of the disclosure will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention together with objects and advantages thereof, may best be understood by reference to the following description of the embodiments together with the accompanying drawings in which:

FIG. 1A is a perspective view of a ring of a spinning machine according to an embodiment of the present invention;
FIG. 1B is a partially enlarged perspective view of the ring of FIG. 1A;
FIG. 1C is a schematic sectional view of a sliding contact between the ring and a traveler during a spinning operation of the spinning machine of FIG. 1A;
FIG. 2A is a plan view of a substrate surface in which dimples are formed by laser processing;
FIG. 2B is a schematic view depicting lapping processing, which is one of rubbing processes;
FIG. 2C is a schematic sectional view of the substrate surface, illustrating a state of the substrate surface after lasered and a state of the substrate surface after lapped;
FIG. 3 is profiles of samples depicting a section of the lapped surface;
FIG. 4 is a schematic diagram depicting a state of a ball-on disk friction test (BOD test);
FIG. 5A is a graph showing a relationship between a sliding distance and a friction coefficient obtained by the BOD test;
FIG. 5B is a scatter diagram showing a relationship between a curvature radius of a projection and a sliding distance when the friction coefficient is 0.6 or less;
FIG. 6 is a bar graph showing a relationship between a sliding distance and a wear depth of a ball (amount of wear of a counterpart);
FIG. 7 is an image (SEM image) of a textured surface of a sample 6 viewed under a scanning electron microscope (SEM) after the BOD test;
FIG. 8 is a scatter diagram showing a correlation between the sliding distance obtained by the BOD test (basic test) and a sliding distance obtained by an actual machine test;
FIG. 9A is a graph showing a relationship (another example) between a sliding distance and a friction coefficient obtained by the BOD test; and
FIG. 9B is a SEM image of a textured surface of another example viewed under the SEM after the BOD test.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Ring of a spinning machine

(1) The present invention relates to a ring of a spinning machine. The spinning machine is configured to wind a yarn through a traveler. The ring has a sliding surface on which the traveler slides. The sliding surface has a texture having a plurality of recesses and a plurality of projections, and each projection having a curved shape and is located between adjacent recesses. The projection has a curvature radius of 40 to 400 µm.
(2) The ring of the spinning machine according to the present invention (hereinafter referred to as ring) achieves a long sliding distance (operating time) with low friction between the ring and the traveler even in a dry state. This enables extension of lifetime of the ring and the traveler, thereby allowing the spinning machine to operate at high speed for a long time, which leads to productivity enhancement of the spinning machine.
(3) The reason why such an effect is obtained is not always clear, but at present, it is presumed as follows. Some fibers (mainly cellulose) generated from a yarn during spinning are interposed between the ring and the traveler sliding on the ring, and contribute to reduction of friction or abrasion between the ring and the traveler. The recesses formed in the texture temporarily catch and retain the fibers to stabilize the sliding state of the ring and the traveler.

Ring and traveler

FIGS. 1A to 1C illustrate a ring 11 and a traveler 12 of a ring spinning machine. The ring 11 has a flange 11a having a substantially T-shaped cross section. The traveler 12 has a substantially C-shaped cross section and is slidably engaged with the flange 11a. The ring 11 and the traveler 12 are made of steel. The ring 11 has a (hard) chrome plating layer 13 on a surface (sliding surface) of the flange 11a. The chrome plating layer 13 has a thickness of 3 to 20 µm, and more preferably 10 to 15 µm.
As illustrated in FIG. 1C, a yarn Y delivered from a draft part (not illustrated) passes through the traveler 12 and is wound on a bobbin (not illustrated) rotating at high speed. The traveler 12 is glided and slid on the chrome plating layer 13 of the flange 11a by the winding tension of the yarn Y Although the traveler 12 can slightly change its sliding posture depending on the rotational speed thereof, in the normal spinning operation, the traveler 12 is in slidably contact with a lower inner surface of the flange 11a as illustrated in FIG. 1C. Even in the normal spinning operation, the maximum rotational speed of a spindle increases to approximately 25,000 rpm.

Texture

(1) A texture is formed on at least a part of a sliding surface of the ring 11 or the traveler 12, wherein the traveler 12 glides on the ring 11. For example, when the ring 11 has the texture, the texture may be formed on a whole surface of the ring 11, but at least formed on the inner peripheral surface (and lower surface of the inner peripheral surface) of the flange 11a.
(2) The texture has a plurality of recesses and a plurality of projections. The size of an area on which the texture is formed may be adjusted according to a sliding state of the ring 11 and the traveler 12. For example, the texture may be formed on a portion of the ring 11 with which the traveler 12 is mainly in contact. The portion of the ring 11 may be formed into a ring shape having a width of 1 to 5 mm, and more preferably a width of 2 to 3 mm, for example.

The recesses (or projections) formed in the texture may be present in a field of view (263 µm × 350 µm) observed under a microscope at a density of 15 to 25 recesses and more preferably at a density of 17 to 22 recesses. The presence of each recess is determined by, for example, whether or not the substantially center of the recess (the deepest point of the recess in its longitudinal cross section i.e., cross section perpendicular to the sliding of the traveler 12 on the ring 11) is within the field of view.
The plurality of recesses may be arranged regularly or irregularly. The regular arrangement of the recesses may be a rectangular arrangement or a staggered arrangement, for example. Each recess may have the same shape or a different shape. The recess having the same shape may be the same size or a different size.
The distance between the adjacent recesses is determined based on the distance between the deepest points of the recesses. Specifically, the distance between the adjacent recesses (i.e., pitch) viewed in the field is set to the arithmetic mean value of distances between the substantially centers of the recesses on an arbitrary straight line passing through the substantially centers of the recesses. The pitch thus obtained is, for example, 40 to 100 µm, 45 to 90 µm, and more preferably 55 to 80 µm. The recesses are preferably arranged regularly. The accuracy of dimension (tolerance) in the present description is about ±20% of the objective dimension.
The opening of each recess (outline of the opening on the surface) may have a circular shape, an elliptical shape, or a square shape. The representative is a circular shape. The size of each recess is determined based on the longest width of each dimple (which is the recess before the adjacent curved projection is formed). Specifically, the size of each recess viewed in the field is determined based on the arithmetic mean value of longest widths of the dimples (referred to as "dimple diameter" regardless of the shape of each dimple). The dimple diameter is preferably 10 to 80 µm, and more preferably 30 to 60 µm, for example.
The depth of each recess is also determined based on the depth of the dimple from the peripheral edge to the deepest point. Specifically, the depth of each recess viewed in the field is determined based on the arithmetic mean value of depths of the dimples (which is referred to as a dimple depth). The dimple depth is preferably 2 to 12 µm, and more preferably 4 to 10 µm, for example.
The curvature radius of each projection is determined based on the curve near the top of the projection (outermost surface) shown in the longitudinal cross section. Specifically, the radius of curve near the top of the projection is approximated, and the approximated value is regarded as the curvature radius of the projection. The radius of curve near the top of the projection is approximated by the method of least squares. The top of the projection refers the contact point between the projection and a plane near the projection (reference plane). The reference plane is, for example, a plane in contact with or closest to at least three recesses (edges of the openings).
For each projection viewed in the field, the arithmetic mean value of the curvature radiuses of the projections on the longitudinal cross section passing through the centers of the recesses serve as the curvature radius in the present description. The curvature radius is preferably 40 to 400 µm, 45 to 370 µm, 50 to 330 µm, and more preferably 80 to 280 µm, for example.
(3) The texture can be formed by various methods. The texture is preferably formed, for example, through a step including a first step for forming a plurality of dimples in a surface of the ring 11 and a second step for rounding a peripheral edge of each dimple and/or a portion of the ring between adjacent dimples.
In the first step, for example, a surface of a base material of the ring 11 or the traveler 12 is irradiated with a high-energy beam (for example, a laser, an electron beam, or the like). The high-energy beam uses, for example, a short pulse laser beam (femtosecond, picosecond, nanosecond, or the like). As an example, a nanosecond pulse laser with a pulse width of 1 to 100 ns, and more preferably 5 to 50 ns, is preferably used as the pulse laser beam, for example.
In the second step, for example, the surface with the dimples is rubbed. The rubbing may be mechanical process or chemical process (chemical etching). The mechanical process using loose grains includes shooting (shot-blasting, shot-peening, or the like), barrel finishing, lapping, and polishing. In rubbing, appropriate abrasive grains (in material, shape, and size) and method (tool, device, or the like) may be selected to form each curved projection between adjacent dimples while preventing elimination of the dimples formed in the first step. In the second step after the first step, for example, the surface with the dimples may be treated by shooting the abrasive, such as blasting or lapping.
The texture (i.e., projections and recesses) can be controlled by selection or adjustment of a rubbing method, amount (time), or the like. For example, as a rubbing time (amount) per unit area increases, the curvature of each projection increases (the curvature radius of the projection decreases) and the curvature of each recess decreases.

Chrome plating layer

The sliding surface may be coated with a chrome plating layer. The chrome plating layer enhances the tribological property (abrasion resistance, or the like) of the sliding surface. The above-mentioned texture may be formed on the chrome plating layer. The surface texturing may be applied to the surface before or after chrome plating. The chrome plating described in the present description is so-called hard chrome plating (functional chrome plating or industrial chrome plating in accordance with Japanese Industrial Standard (JIS)).
The chrome plating layer may have a film thickness of 3 to 20 µm, and more preferably 10 to 15 µm, for example. The chrome plating layer may have a hardness of 850 to 1,050 HV, and more preferably 900 to 1,000 HV, for example. The correlation between the hardness and the abrasion resistance of the chrome plating layer is not always clear. However, the abrasion resistance cannot be increased if the hardness is excessively small, and the amount of wear of the traveler 12, which is the counterpart of the ring 11, may be increased if the hardness is excessively large.

Others

(1) The ring 11 and the traveler 12 may be made of any material. For example, the ring 11 may be made of carbon steel or alloy steel. For example, the traveler 12 may be made of spring steel or high-carbon steel. The traveler 12 may be heat-treated (oxidatively treated) to prevent adhesion of the traveler 12 to the ring 11 as a sliding counterpart of the traveler 12.
(2) Yarn (fiber)

A yarn that slidably comes in contact with the traveler 12 may be made of any material. However, if it is presumed, the yarn is made of material, preferably, which can naturally supply lubricating components under non-liquid lubrication (dry state) in the atmosphere, such as cotton, hemp, silk, wool, or chemical fiber (e.g., cellulose nitrate, nylon, vinylon).
The ring 11 may be used for spinning of thick yarn other than spinning of thin yarn. If a heavyweight traveler is used for spinning of thick yarn, a desired tribological property can be secured by combination of the traveler with the ring 11 according to the present invention.

EXAMPLES

Outline

For evaluation, disks (samples) were prepared in such a manner that substrates of disks were textured after surfaces of the substrates, which will serve as the sliding surfaces during the test, were chrome-plated. On a basic test, the tribological property (sliding distance with low friction) was evaluated by a ball-on disk friction test (BOD test) conducted under non-liquid lubrication (dry state).
Further, on an actual machine test, a ring having a sliding surface on which a texture was formed was mounted to a ring spinning machine, and the tribological property of the texture was evaluated. The following will describe the details of the tests for elaborating the present invention.

Basic test

Sample preparation

(1) Substrate

Each substrate (ϕ30 mm × 5 mm thick) was made of bearing steel (SUJ2 specified in JIS), which was the same as that of the ring of the spinning machine. The surface of the substrate was finished by mirror finishing so as to have a surface roughness of Ra 0.08 µm.

(2) Chrome plating

The finished surface was chrome-plated. The chrome plating was performed by electroplating using a high-speed bath. The film thickness of the chrome plating layer of each sample was set to approximately 13 µm. The film thickness was determined based on the measurement result of the abrasion marks, which was measured by the Calotest manufactured by Anton Paar GmbH under the brand name of CSM instruments after the sliding test was conducted.

(3) Texture

The texture was formed on the central area (a 10-mm square area centered on the center) of the chrome plating layer as follows. First, approximately semispherical dimples each having an approximately circular opening were regularly (periodically) formed on the chrome plating layer by a nanosecond pulse laser or a femtosecond pulsed laser (in the first step). The dimples were staggered mutually. Each sample had dimples of different sizes, but the same sample had dimples of the same size. FIG. 2A shows an example of the staggered dimples having the same size. The dimple size of each sample (diameter, pitch, depth) is shown in Table 1. The dimples were staggered mutually at one-half pitch (P/2 µm). For comparison, another sample without textured was prepared.
Next, the surface of each sample in which the dimples were formed was rubbed (in the second step). The surface of each sample was rubbed by a lapping machine (AERO LAP manufactured by Yamashita Works co., Ltd.). Specifically, as illustrated in FIG. 2B, abrasives (Multi Cone manufactured by Yamashita Works co., Ltd.) were shot onto the surface. The abrasives were abrasive grains (particle size: a few millimeters) each made by adhering diamond grains (particle size: 2 to 4 µm) to a food material as a core.
The abrasives were delivered at a constant conveyor speed of 120 mm/s and shot onto the surface. The rubbing level was adjusted by controlling the movement speed of the nozzle relative to the surface (referred to as scanning speed). The abrasives were shot at an angle of approximately 45 degrees onto the surface. The distance between the tip of the nozzle and the surface was set to approximately 50 mm.
FIG. 2C schematically illustrates changes in a state of the texture after lasering (in the first step) and rubbing (in the second step). By rubbing the surface of each sample, a flat surface of the portion between the adjacent dimples was formed into a curved projection, and each dimple was formed into the recess having a rounded peripheral edge.
FIG. 3 depicts changes in the shapes of the projection and the recess according to the scanning speed. FIG. 3 depicts profiles that were obtained from measurements of the longitudinal cross section of the rubbed substrate surface by 3D shape measuring instruments (NewView 5022, manufactured by Zygo Corporation). FIG. 3 clearly shows that the texture had the projections each having a decreased curvature radius that smoothly continues to the recess each having an increased curvature radius, because the shot abrasive grains came in contact with the surface for a longer time as the scanning speed decreased.
Table 1 shows the curvature radius of the projection of each sample obtained from the measurements shown in FIG. 3. The curvature radius of the projection was obtained by approximating the radius of the curve (curved surface) near the top of the projection.

Sliding Test

The ball-on disk test (BOD test) was performed by Tribometer, manufactured by Anton Paar under the brand name of CSM instruments, in the base test in such a manner that a ball slid on the disk of each sample. FIG. 4 schematically illustrates this test. The ball (ϕ6 mm) made of bearing steel (SUJ2 specified in JIS) had a surface roughness of 0.08 µmRz_JIS and a surface hardness of HV 800 (test load: 100 g).
The sliding conditions were as follows: test load of 4 N (maximum hertz surface pressure: 1,036 MPa); sliding velocity of 0.2 m/s; sliding environment of non-liquid lubrication (dry state) in the atmosphere. The ball slid on the disk on a circumference of a circle with a sliding radius of 4 mm from the center of the disk. The friction coefficient (µ) was calculated from the measured value (friction force), which was obtained by the friction resistance sensor on the ball, and the test load.
The sliding test was performed as follows. First, the ball came into direct contact with the disk of each sample in the dry state. The cellulose was supplied to the sliding area after the ball slid on the disk 5 m, and the ball further slid on the disk 100 m (total sliding distance: 105 m).
Specifically, the cellulose was supplied by drops of a cellulose suspension onto the sliding area. The cellulose suspension was prepared in such a manner that cellulose powder (average particle size of 24 µm), KC FLOCK manufactured by Nippon Paper Industries Co., Ltd., was dispersed in a hydrofluoroether solvent (C₄F₉OCH₃), Novec 7100 manufactured by 3M. The cellulose powder and the solvent were mixed with a compound ratio of 122 mg to 25 mL and stirred by an ultrasonic cleaner to prepare the suspension. The cellulose suspension was dropped 200 µL every testing. The drops of the suspension spread and naturally dried on the disk of each sample.
Every sample was tested for measuring changes in the friction coefficient relative to a sliding distance. The measurement results were shown graphically in FIG. 5A. In each sample, the friction coefficient returned to 0.6 after once decreased by the dropping of the cellulose. The sliding distance of the ball on each sample at the friction coefficient of 0.6 (sliding distance at µ ≤ 0.6) was determined. The measurements are shown in Table 1 and FIG. 5B.
After the sliding test, a wear diameter made on a sliding surface of the ball was measured. The wear diameter of the ball was measured when the sliding distance after the dropping of the cellulose reached to 10 m (total sliding distance: 15 m) and when to 100 m (total sliding distance: 105 m). For some samples, FIG. 6 shows the wear diameter of the ball converted into the wear depth of the ball (decrease in diameter).
Further, FIG. 7 shows a SEM image of a sample 6 of observing the sliding surface of the disk after the sliding distance reached 10 m (total sliding distance: 15 m).

Evaluation

(1) Table 1, FIGS. 5A and 5B clearly show that the curvature radius (R) of each projection of the texture formed on the sliding surface is correlated with the sliding distance until the friction coefficient reaches 0.6 (i.e., µ ≤ 0.6). That is, the measurements have shown that the sliding distance increased remarkably when the curvature radius (R) was within a predetermined range.
(2) FIG. 6 clearly shows that the amount of wear of the ball serving as the sliding counterpart was also reduced when the curvature radius (R) was within the predetermined range. Accordingly, it was found that the presence of the texture having projections with a curvature radius (R) within a predetermined range on the sliding surface enhanced the tribological property significantly. As shown in FIGS. 5A and 7, it is presumed that fibers (cellulose in this example) caught in the sliding surface having the texture affects the tribological property.

Actual machine test

(1) Conditions

The ring having the texture (shown in Table 2) on the sliding surface and the traveler were mounted to an actual machine (ring spinning machine RX240 manufactured by Toyota Industries Corporation), and the sliding distance at the end of the traveler's life was measured. Table 2 shows the test results. In testing, the actual machine was operated at a maximum rotation speed of 21,000 rpm in a dry environment. The lifetime of the traveler was defined as when the initial thickness (t) of the traveler was halved (0.5 t), and was shown by the sliding distance up to that time.
Disks having the same texture were prepared and tested by the BOD test in the same manner as the basic test. The test load was 2 N (maximum hertz surface pressure: 822 MPa). In this way, the sliding distance until the friction coefficient returned to a value in the range of 0.8 to 0.9 was determined for each sample. Table 2 also shows this test results. The sliding radius (sliding position of the ball on each disk) was set to 4 mm and 8 mm. When the sliding radius was set to 8 mm, the texture is formed on each disk in a 20-mm square area centered on the center of the disk.
In the above-mentioned BOD test, 100 mg of cellulose powder was dropped onto the center of the rotating disk immediately after the ball slid on the disk 5 m in a dry state. Cellulose particles of the dropped cellulose collide with the ball (steel ball) while scattering outwardly. Then, the cellulose particles are pressed by the disk and the ball, and lubricate the ball and the disk to facilitate sliding of the ball on the disk. Due to the difference in scattering speed of the cellulose particles, more cellulose particles are supplied to the area with a large sliding radius (8 mm) than to the area with a small sliding radius (4 mm). Accordingly, the cellulose particles cause the lubricity to be higher in the area with the large sliding radius than in the area with the small sliding radius.

(2) Result

FIG. 8 shows the results of the BOD test and the actual machine test indicated in Table 2. FIG. 8 clearly shows that there is a correlation between the results of both the tests when the same texture is formed on the sliding surface. That is, the results have shown that the BOD test substitutes for the actual machine test.

Supplemental test

Another BOD test (test load: 4 N) was conducted with an extended sliding distance. FIG. 9A shows this test results. Preparatory for this test, the sliding surface of the disk used in this BOD test was lasered to have dimples (D: 40 µm, P: 70 µm, H: 4 µm) in the sliding surface, and the dimples were rubbed to have the texture in which projections with curvature radius (R) of 86 µm were formed.
FIG. 9B shows the SEM image of the sliding surface after the test was conducted. The SEM image has demonstrated that the wear diameter of 347 µm (5 µm in terms of wear depth) was formed on the sliding surface of the ball by the test. Further, another test was conducted by using a disk without texture. In the test, the wear diameter of the ball was 412 µm (wear depth: 7.1 µm) when the sliding distance was 100 m, and 463 µm (wear depth: 8.9 µm) when the sliding distance was 200 m.
These test results have shown that the fibers in a texture provides stable lubrication effect when the sliding surface has the texture in which projections with a curvature radius within a predetermined range are formed, thereby allowing extension of a sliding distance with low friction, which leads to reduction in wear of the sliding counterpart.
Unlike the conventional art that has a flat surface between adjacent recesses, the present invention has a curved projection with a predetermined curvature formed between adjacent recesses. This allows the traveler to slide on each smoothly curved projection of the ring (specifically, near the top of the projection). This further allows the fibers caught in each recess to be guided from the recess to the adjacent projection, which smoothly continues from the recess, and easily supplied to a vicinity of the top of the projection where the traveler slides on the ring. It is considered that these act synergistically to enhance the tribological property of the ring and the traveler (friction reduction, abrasion reduction, etc.), thereby achieving a long sliding distance with low friction.

Others

(1) The present description mentions an exemplary embodiment of a ring having a texture, but the traveler may have the texture. Further, both the ring and the traveler may have the texture. Accordingly, the present invention does not only relate to a ring of a spinning machine only, but may also to a traveler of a spinning machine, or a ring and traveler system of a spinning machine. The present invention may further relate to a spinning machine, such as a fine spinning machine or a roving machine, including such a ring and/or a traveler.
(2) Unless otherwise specified, a numerical range of "x to y" as tolerance mentioned in the present description includes a lower limit value "x" and an upper limit value "y". Within the numerical range of "x to y", another numerical range of "a to b", including another lower limit value "a" and another upper limit value "b" may be newly established as mentioned in the present description. Further, a numerical range such as "x to y µm" means "x µm to y µm unless otherwise specified. The same applies to other unit systems.

Table 1

TABLE 1

SAMPLE No.	TEXTURE				EVALUATION
	DIMPLE BEFORE LAPPING			PROJECTION AFTER LAPPING	SLIDING DISTANCE WHEN µ ≤ 0.6
	D: DIAMETER (µm)	P: PITCH (µm)	H: DEPTH (µm)	R: CURVATURE RADIUS (µm)	SLIDING DISTANCE WHEN µ ≤ 0.6
1	40	70	6	87	84
2			6	97	119
3			6	91	130
4			4	203	55
5			6	273	46
6	30		8	140	58
7	30		8	198	44
8	40	70	4	112	54
9	40	70	4	148	46
C1	30	70	8	423	36
C2	20	40	6	38	7
C3	10	30	4	13	13
C4	40	100	6	1960	35
C5	30	100	6	2334	12
C6		70	2	440	35
C7		70	2	469	37
C01	NO TEXTURE (FLAT)			2800	34
C02				2820	3
C03				2840	2

TABLE 2

SAMPLE No.	TEXTURE				EVALUATION
	DIMPLE BEFORE LAPPING			PROJECTION AFTER LAPPING	BOD TEST		ACTUAL MACHINE TEST
	D: DIAMETER (µm)	P: PITCH (µm)	H: DEPTH (µm)	R: CURVATURE RADIUS (µm)	SLIDING DISTANCE (m) WHEN µ ≤ 0.8-0.9		SLIDING DISTANCE (TRAVELER'S LIFETIME) (x 10⁴ m)
	D: DIAMETER (µm)	P: PITCH (µm)	H: DEPTH (µm)	R: CURVATURE RADIUS (µm)	SLIDING RADIUS 8 mm	SLIDING RADIUS	SLIDING DISTANCE (TRAVELER'S LIFETIME) (x 10⁴ m)	4 mm
A1
	10	70	4	1960	64	20	1.81
A2	20	70	2	440	74	129	3.61
A3	10	30	4	120	118	129	3.61
A4	20	70	4	397	138	162	3.97
A0	NO TEXTURE (FLAT)				58	15	1.81

Claims

A ring (11) of a spinning machine, the spinning machine being configured to wind a yarn (Y) through a traveler (12), the ring (11) comprising:
a sliding surface on which the traveler (12) slides,

wherein the sliding surface has a texture having a plurality of recesses and a plurality of projections, and each projection has a curved shape and is located between adjacent recesses,

characterized in that

the projection has a curvature radius of 40 to 400 µm.
The ring (11) of the spinning machine according to claim 1, characterized in that a distance between the adjacent recesses is 40 to 100 µm.
The ring (11) of the spinning machine according to claim 1 or 2, characterized in that the sliding surface has a chrome plating layer (13).
A method for manufacturing the ring (11) of the spinning machine according to any one of claims 1 to 3, the method for manufacturing the ring (11) comprising: a step for forming the sliding surface, characterized in that the step for forming the sliding surface includes:
a first step for forming a plurality of dimples in a surface of the ring (11); and

a second step for rounding a peripheral edge of each dimple and/or a portion between adjacent dimples.
The method for manufacturing the ring (11) of the spinning machine according to claim 4, characterized in that in the first step, the surface of the ring (11) is irradiated with a laser to have the dimples.
The method for manufacturing the ring (11) of the spinning machine according to claim 4 or 5, characterized in that in the second step after the first step, the surface of the ring (11) is rounded by shooting an abrasive onto the surface of the ring (11).