Wet end seal material for linear motion mechanism and linear motion mechanism using said seal material

Abstract

The present invention provides an end seal material for a linear motion mechanism that has high dust resistance and lubricity even when exposed to fine dust particles of a few microns in size, such as paper dust, which detracts from lubrication, and in particular provides an end seal member that maintains dust resistance and lubricity for a long period of time, is easy to install and replace, is simple and easy to handle, and has high tracking and a wide adjustment range.The end seal material 9 is attached to both ends of a slider 8 of a linear motion mechanism 6 consisting of a rail 7 and a slider 8, and the end seal material 9 has a support frame 11 arranged on the outer periphery of the rail 7, a base fabric part 12 whose back surface is fixed to the inner periphery of the support frame 11, and cut pile 10 protruding from the surface of the base fabric part 12, the tips of the cut pile 10 bent to contact the rail so as to seal the gap between the rail 7 and the support frame 11, and a lubricant is previously held between the pile fibers of the cut pile 10.

Description

[Technical field]

[0001] The present invention relates to a wet end seal material for a linear motion mechanism and a linear motion mechanism using said seal material. A linear motion mechanism is an essential component for mechanisms that require high positioning accuracy while reducing friction, or other mechanisms that perform linear motion. A typical example of such a mechanism is a linear guide device, also known as a linear guide, linear guide, or LM guide (registered trademark).

[0002] This linear motion mechanism is broadly composed of two elements, a shaft and a slider. The slider moves smoothly back and forth linearly on the shaft, and "rolling elements" or "rollers" are arranged inside the slider at the contact points with the shaft. The linear motion mechanism of the present invention, which is equipped with a slider and a shaft, includes a mechanism using a linear motion guide rail with rolling grooves on a shaft with a rectangular cross section, such as a linear motion guide device (linear guide, linear guide, LM guide), a linear bush in which a slider slides back and forth in the axial direction on a cylindrical shaft, and a ball spline using a spline shaft in which balls roll in grooves provided on the surface of the cylindrical shaft, thereby increasing the allowable load.

[0003] In the following, a linear guide will be described as a representative example of a specific example of a linear motion mechanism, but the present invention relates to a wet side seal material that can be applied to any linear motion mechanism and a linear motion mechanism using this seal material. That is, the present invention relates to a wet seal material that is attached to both ends of the slider part with pile parts that bite into the rolling surface, prevents foreign matter from entering the drive part during linear motion or rotation, and simultaneously applies grease to the rolling surface to prevent dust and contribute to a longer life, and a linear motion mechanism using this. [Background technology]

[0004] Now, in mechanical motion, there are linear motion and rotary motion, and positioning mechanisms are known for each. Compared to rotary motion, which is widely used in practical applications such as bearings, it has been technically very difficult and advanced to put rolling elements for linear motion into practical use. Of course, if rolling elements could be used for linear motion, it would be useful because it would have a small rolling friction coefficient and low starting resistance. However, to actually put it into practical use, it is necessary to provide a mechanism for linear motion that satisfies all of the requirements, such as high rigidity, labor-saving and high-speed, smooth operation, high positioning accuracy, and a long life. It has not been easy to satisfy the practical required accuracy. Therefore, even now, further ingenuity is needed to meet these requirements.

[0005] Since the linear motion mechanism is a mechanical element that requires the slider to move smoothly, stably, and precisely on the shaft for a long period of time, it needs to have sufficient durability, and for this reason, lubrication and dust resistance are important. For example, if powder or foreign matter gets inside the slider, the slipperiness of the rolling body will deteriorate, and the life of the slider will be significantly reduced. In addition, the increase in friction will lead to malfunction. Since linear motion mechanisms are often used in environments where there is a large amount of dust such as powder and cutting foreign matter, there are many situations where problems are likely to occur, which may lead to malfunction of the entire machine or device using the linear motion mechanism.

[0006] Therefore, a mechanism has been proposed in which the entire device having the rolling elements is covered with bellows to prevent foreign matter from entering the device so that the device can continue to operate even when used in an environment where a large amount of powder or foreign matter is present. However, covering the device with bellows means that a large area of ​​the device is covered, and the bellows must be removed, making it difficult to maintain. In addition, even if the device is covered with bellows, it is not easy to completely prevent the intrusion of powder or foreign matter, and any powder or foreign matter that enters the inside of the bellows will immediately cause malfunctions, making it difficult to reduce the frequency of maintenance.

[0007] Therefore, in order to prevent powder or foreign matter from entering the slider part of the linear guide and causing malfunction, sealing members made of synthetic rubber such as nitrile rubber, resin, metal scrapers, brushes, or a combination of these are placed at the ends of the slider or in the gap between the slider and the rolling elements, or sealing material made of synthetic resin and made of an elastic body installed so as to abut against the plate is placed between the inner and outer plates of the chain (see, for example, Patent Document 1).

[0008] However, a small gap is likely to occur between the seal member and the rolling surface of the slider, and in order to reduce the gap, the seal member must be manufactured precisely to a specified shape in advance, which increases the manufacturing cost of the seal member. In addition, since the seal member itself is made of a solid material such as rubber, it is likely to be chipped or deformed by foreign matter, and once a chip occurs, there is a concern that a large amount of foreign matter will flow in from the chipped area. In addition, it is not easy to make an adjustment to ensure precise sealing, and if an attempt is made to eliminate the gap by using a jig or the like to abut against the rail when installing the seal unit so that it functions as a seal material, this will result in an increase in the added torque, which will cause problems such as increased friction during reciprocating motion.

[0009] In addition, in the current seal unit of the linear motion mechanism, the seal and the lubrication are separate parts. In addition to the end seal, a mechanism is provided to continuously supply grease from a grease retention mechanism such as nonwoven fabric or fiber net, which increases the installation dimensions and causes loss in the driving range, which is also one of the reasons for the increase in size of the device. In addition, if the grease is absorbed into powder or foreign matter and becomes a mass, it can cause chipping or deformation of the sealing material, which can cause malfunction of the linear motion mechanism in situations where there is insufficient sealing performance.

[0010] Furthermore, repeated movement can cause deformation and wear of the seal material, which can then be scraped off and impair its sealing function, leading to malfunctions caused by the leakage of lubricant and the intrusion of powder and foreign matter into the slider. Therefore, frequent cleaning and replacement of the seal material and the grease used for lubrication have become virtually essential for stable operation, which has tended to increase maintenance costs.

[0011] Even if the linear guide is frequently cleaned and the sealing members and grease used for lubrication are replaced, when the linear guide becomes worn due to powder or foreign matter, the replaced sealing member does not abut and a gap is created. Large amounts of powder or foreign matter get into this gap, making the linear guide, the guide mechanism with the ball screw, and the chain themselves unusable, and making it necessary to replace the device itself.

[0012] The applicant has therefore proposed a side seal unit for a linear motion mechanism in which the ground yarn part of the cut pile with a warp and weft double weave structure consisting of two layers, a surface layer of surface warp and surface weft, and a back layer of back warp and back weft, is fixed to the inner side of the base, and the tips of the pile fiber loops that are raised further toward the inner side from the ground yarn part of the cut pile are cut and raised to form cut pile hairs that are arranged to abut against the cross-sectional shape of the shaft, and sealing material made of cut pile is arranged at the front and rear ends of the slider (see, for example, Patent Document 2).

[0013] However, there are cases where the cut pile alone is not sufficient to seal out powder and foreign matter for a long period of time. For example, in an environment containing fine powder that absorbs the lubricant, like paper dust, the dry cut pile slides and is unable to maintain sufficient dust-proofing, so there is a demand for even stronger seal retention. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] JP 2011-231843 A [Patent Document 2] WO2015 / 086138 publication Summary of the Invention [Problem to be solved by the invention]

[0015] Therefore, the problem to be solved by the present invention is to provide an end seal material for a linear motion mechanism having high dust resistance and lubricity for a linear motion mechanism with high positioning accuracy and long life. In particular, it is to provide an end seal member that can maintain dust resistance and lubricity for a long time even in a poor environment where there is not only fine powder of several μm but also fine dust such as paper powder of several μm that absorbs the lubricant and deprives it of lubricity. And, it is an end seal member that can more easily retain lubricant and maintain its supply for a long time. In addition, it is to provide a linear motion mechanism equipped with an end seal member that is easy to install and replace, has a simple and easy-to-handle structure with high maintainability. That is, it is to provide a seal material with high followability that can be easily installed without the need to strictly adjust the abutment state during assembly, and to provide a seal material that has high followability to wear and complex shapes of sliding parts such as shafts, has a wide adjustment range, and is easy to adjust, and is a linear motion mechanism using such a seal material. In addition, in the past, maintenance such as removing and replacing the sealing material required appropriate adjustment of the clearance to ensure smooth movement of the slider, and replacement had to be done by an experienced person. Therefore, the object of the present invention is to provide a sealing material with a large adjustment range that allows for easier removal and replacement, and that can easily ensure shielding properties even with rough installation. [Means for solving the problem]

[0016] The first means for solving the problems of the present invention is An end seal material to be attached to both ends of a slider of a linear motion mechanism consisting of a rail and a slider, The end seal material is A support frame disposed on the outer periphery of the rail; A base fabric portion having a back surface fixed to an inner peripheral surface of the support frame; The fabric has cut pile protruding from the surface of the base fabric, The ends of the cut pile are bent to close the gap between the rail and the support frame and come into contact with the rail, A lubricant is held between the pile fibers of the cut pile in advance. This is an edge sealing material made of wet cut pile, characterized by the above.

[0017] A second aspect of the present invention is the end seal material according to the first aspect, characterized in that the lubricant held between the pile fibers of the cut pile is a grease having a JIS K2220 consistency number of 1 to 4. That is, the mixed consistency range of the grease is 175 to 340. Furthermore, the grease may also be held in the base fabric of the cut pile.

[0018] The third aspect of the present invention is the end seal material according to the second aspect, characterized in that the grease is any one of lithium grease, grease containing a molybdenum compound, and urea-based grease. The lithium grease is a lithium soap-based grease, which may further contain molybdenum disulfide. The urea-based grease is, for example, diurea grease, triurea grease, and tetraurea grease.

[0019] The fourth aspect of the present invention is the end seal material according to any one of the first to third aspects, characterized in that the pile length of the cut pile is 2 mm or more. Since the pile tip has a length that allows it to bend and bite into the gap between the inner circumference of the support frame and the rail, the pile length is preferably 2 mm or more as the length that allows it to bend in the gap. More preferably, it is 3 mm or more.

[0020] The fifth aspect of the present invention is the end seal material according to any one of the first to fourth aspects, characterized in that the pile fibers of the cut pile are composed of crimped multifilament fibers. In addition, the cross section of each filament of the crimped pile fibers is preferably a cross-sectional shape that has a larger surface area, such as a star-shaped, *-shaped, hollow cross-section, or a modified cross-section other than a round cross-section.

[0021] A sixth aspect of the present invention is the end sealing material according to any one of the first to fifth aspects, characterized in that the cut pile is made of a woven fabric.

[0022] A seventh aspect of the present invention is the end sealing material according to any one of the first to fifth aspects, characterized in that the cut pile is made of knitted fabric.

[0023] An eighth aspect of the present invention is a linear motion mechanism comprising a rail and a slider, in which the end seal material according to any one of the first to seventh aspects is detachably and replaceably fixed to both ends of the slider. Effect of the Invention

[0024] According to the above-mentioned means for solving the problems of the present invention, the end seal material is in a state where a lubricant is held in advance, and the tips of the pile of the cut pile are bent in contact with the rail. That is, the tips of the pile are bent and bitten in the gap between the rail and the inner circumference of the support frame, so that the adhesion is high and the gap is firmly blocked during the linear motion, so that it is possible to prevent foreign matter such as fine powder and dust from entering the slider. Furthermore, since the lubricant such as grease is held in advance between the pile fibers, and the pile can hold the lubricant for a long time even after the linear motion, the tips of the piles that are bitten in the gap slide smoothly due to the lubricant, so that the movement is unlikely to become poor due to friction, and the lubricant is held between the piles in a state where it does not interfere with the smooth movement of the slider, and the shielding effect is enhanced with viscosity, so that a high dustproof effect can be obtained for a long time. In other words, rather than being applied as a lubricant for smooth operation, the grease acts as a moisturizer to maintain shielding properties and is retained between the pile and in the base fabric, giving the tips of the fibers an appropriate viscosity when moist, resulting in high shielding properties for a long period of time.

[0025] Furthermore, if the lubricant for retaining the shield is a grease of appropriate consistency, a sufficient amount can be retained between the pile fibers in advance, and the grease can be maintained between the fibers for a long period of time even after linear motion or other sliding, allowing the pile to be equipped with a viscous wet shield and to stably retain its shielding properties for a long period of time.

[0026] Also, if the lubricant held between the piles is a grease of appropriate consistency, it can keep out fine powders and dust particles of a few microns for a long period of time.Even with dust particles of a few microns, such as paper powder, which can cause the paper fibers to absorb oil, the grease is not absorbed too much by the paper fibers and can maintain a certain level of moisture, and the piles can maintain their state of retention of grease, so sealing and lubrication are not impaired, and the slider will continue to operate smoothly for a long period of time.

[0027] The tip of the shielding bristles bends and bites into the gap, so it is easy to prevent the intrusion of dust and the like, and since it slides wet, there is little frictional resistance and it does not hinder the movement of the slider, so there is no problem with bending it to make it fit tightly. Therefore, when removing, replacing, or installing the seal material, it is possible to adjust the clearance by bending the seal material without the need for strict clearance adjustment by an experienced person, so that appropriate shielding properties can be easily ensured. Therefore, when removing and replacing the seal material, which is required periodically, it is not necessary to dispatch an experienced person, but by simply supplying the replacement parts of the seal material to the customer, it is possible to easily replace it without the need for skilled workers, and it is possible to ensure stable shielding properties without the need for adjustment. Since it is easy to remove and attach, maintenance replacement can be carried out at the discretion of the site, and even replacement by a relatively loose amateur can demonstrate the sealing performance.

[0028] That is, the pile of the abutting seal material is easily abutted against the rail evenly due to the repulsive force of the pile fibers when they are bent. Also, the pile tips are bent to bite into the gaps, so the pile repulsive force makes it easy to make the pile uniform when installed. In addition, even if there is some deviation, the pile fills the gap, so the sealing performance is not easily lost, and since a viscous wet lubricant is held around the pile, the sealing performance is more easily maintained. By intentionally making the pile bite in this way, it is easier to adjust and the material is smooth and highly dust-proof compared to materials such as rubber and felt, which have high friction resistance unless the contact adjustment is made strictly.

[0029] In addition, by retaining a lubricant between the pile fibers to exert sealing performance, high shielding properties can be obtained, which in turn reduces the amount of lubricating grease used, making it possible to simplify the lubricating grease supply mechanism on the slider side. Therefore, by using a thin sealing material, the lubricating mechanism can be made more compact, such as by saving space for the oil supply mechanism.

[0030] Furthermore, by making each filament of the pile fiber into a crimped multifilament, the surface area of ​​each pile fiber can be increased, and the grease can be easily entangled between the pile fibers and can be held in large quantities, so that the grease can be used as a source of lubricant for a long period of time and the shielding properties can be maintained for a long period of time.

[0031] Furthermore, when the cut pile is a woven fabric, it is easy to ensure that the base fabric of the cut pile is sufficiently thick, and the base fabric can be made to retain sufficient grease, making it possible to supply sealing lubricant to the pile fibers for a longer period of time.This means that the sealing performance is less likely to deteriorate even if the sealing material needs to be replaced less frequently, and contributes to a longer life for the sealing material and the linear motion mechanism. [Brief description of the drawings]

[0032] [Figure 1] Rebound load curve showing the relationship between Gap (mm) and rebound load (gf) when using type B and type C pile and felt. [Diagram 2] This figure explains one form of end seal material used when the gap to be filled has a curved surface. The figure shows the procedure of inserting a seal member having wet piles containing grease over a length that allows one or two revolutions of the spiral groove of the ball screw into a position facing the spiral groove of the ball screw of one of the divided support frames arranged on the outer periphery of the male screw shaft of the ball screw while rotating it, and then fitting the other divided support frame into it, and then inserting and fixing a plate into the support frame to prevent the wet seal member from coming off. [Diagram 3] The figure illustrates one form of an end seal material used when the gap to be filled has a curved surface. The figure shows the procedure of inserting a seal member having wet piles containing grease over a length that allows at least one to three revolutions of the spiral groove of the ball screw into a support frame disposed on the outer periphery of the male screw shaft of the ball screw, and then inserting and fixing the plate into the support frame to prevent the wet seal member from coming off the support frame. [Figure 4]The figure shows a form of an end seal material used when the gap to be filled has a curved surface. The figure shows a procedure in which a support frame disposed on the outer periphery of the male screw shaft of a ball screw is divided, and a seal member having wet piles containing grease in stripes is disposed at positions to face each of the crests and valleys of the spiral groove of the ball screw, and then the support frame is placed over any position of the ball screw to be integrated. [Diagram 5] The figure explains one form of an end seal material used when the gap to be filled has a curved surface. The figure shows the procedure for inserting and integrating a wet seal material containing grease, in which the piles are cut into stripes along the spiral groove of the ball screw so that they are arranged to face the spiral groove of the ball screw over a length that can be at least one revolution, into a support frame arranged on the outer periphery of the male screw shaft of the ball screw so that they are arranged to face at least the spiral groove of the ball screw. [Figure 6] 1 is a diagram illustrating a state in which end seal materials, a means of the present invention, are attached to both ends of a slider of a linear motion mechanism consisting of a rail and a slider. FIG. [Figure 7] 1A and 1B are diagrams for explaining a method of attaching end seal materials, which are a means of the present invention, to both ends of a slider of a linear motion mechanism consisting of a rail and a slider. [Figure 8] 1 is a cross-sectional view for explaining a state in which end seal materials according to the present invention are attached to both ends of a slider of a linear motion mechanism consisting of a rail and a slider. The slider moves in the left-right direction on the rail. [Figure 9] FIG. 2 is a schematic diagram illustrating a state in which end seal materials according to the present invention are attached to both ends of a slider of a linear motion mechanism consisting of a rail and a slider. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The following is a detailed description of the embodiments of the present invention, with reference to the examples and drawings. As one embodiment of the linear motion mechanism of the present invention, a linear motion mechanism 6 consisting of a linear guide made up of a rail 7 and a slider 8 is shown in Figures 7, 8, and 9. In this linear guide, end seal materials 9 of the present invention are arranged on both ends of the slider 8 so that the tips of the cut piles 10 contact the outer periphery of the rail 7. The end seal materials 9 are covered with an exterior body 14, and the exterior body 14 is fixed to the slider 8 with screws 13.

[0034] The end seal material 9 is arranged at the front and rear ends of the sliding portion of the slider 8 with the rail 7. The back surface of the base fabric portion 12 of the end seal material 9 contacts the inner peripheral surface of the support frame body 11, which is the outer frame, and a countless number of cut piles 10 with protruding bristles are arranged on the surface of the base fabric portion 12. The end seal material 9 is fixed to each end of the slider 8 that moves back and forth. In FIG. 8, the slider 8 moves horizontally, that is, left and right on the drawing, so that the end seal material 9 is arranged at the left and right ends of the slider 8 in FIG. 8. The end seal material 9 is arranged in a state in which the tip of the cut pile 10 is lightly in contact with the surface of the rail 7 so as to cover the front and rear of the sliding portion between the rail 7 and the slider 8. In other words, the cut pile 10 seals the gap between the rail 7 and the slider 8.

[0035] The end seal 9 shown in Figure 8 is formed by attaching the back surface of a base fabric part, with cut pile protruding from the surface of the base fabric, to one side of a rectangular metal plate (e.g. an aluminum plate), and the cut pile can be folded inward and the metal plate outward so that the tips of the cut pile can be aligned with the cross-sectional shape of the rail 7. In this way, the end seal 9 of the present invention, in which the cut pile 10 is arranged around the inner periphery of a U-shaped support frame 11, can be easily obtained.

[0036] A lubricant such as grease is held between the fibers of the cut pile 10 beforehand. Therefore, the end seal material 9 is wet-type and is used with enhanced sealing properties. The lubricant component near the base fabric side of the cut pile can seep out to the tip of the cut pile 10, so that it is appropriately replenished to the contact surface. Therefore, the lubricant component is naturally replenished during sliding with the rail 7, making it a structure that is unlikely to become short of lubrication.

[0037] Furthermore, since the end seal material 9 is simply fixed via the outer casing 14 with screws 13, by loosening the screws 13 that secure it to the slider 8 and removing the outer casing 14, the end seal material 9 can be easily removed for maintenance such as replacement, cleaning, and lubrication.

[0038] In addition, the linear motion mechanism used in the following explanation will be represented by a linear guide since tests were conducted using a linear guide. However, the content also applies to other linear motion mechanisms, and therefore the description should not be construed as limiting the form of the linear motion mechanism.

[0039] <Test Example 1: Confirmation of grease retention and grease supplying ability of pile woven fabric and pile knitted fabric in wet end seal material for linear motion mechanism>

[0040] Materials and Methods

[0041] About the evaluation pile In order to evaluate the grease retention and sealing properties of woven and knitted pile fabrics in wet end seal materials for linear motion mechanisms, five types of woven and knitted pile fabrics were selected for use in the wet end seal materials. The details of the configurations of the selected woven and knitted pile fabrics are shown in Table 1 below.

[0042] [Table 1]

[0043] The pile in the P-type pile fabric in Table 1 uses one type of straight fiber for the raised pile fibers. It has a large fiber diameter among the selected pile woven and knitted fabrics. The density is 378,000 threads per square inch. The ground yarn part of the base fabric that holds the pile in place is a fabric made of weft yarn (nylon / thermal fusion yarn) and warp yarn (nylon), and is a warp-warp double weave consisting of two layers, a surface layer and a back layer. In order to reduce shedding of the cut pile, an acrylic emulsion is permeated into the ground yarn part of the base fabric from the back side.

[0044] The pile in the C-type pile fabric is made of hollow and porous fibers and has a crimping property. The raised pile fiber is a blend of 3.0 denier Biosafe, 1.5 denier Aqualon, and 1.5 denier rayon, with a density of 316,500 per square inch. The ground yarn part of the base fabric that fixes the pile is a fabric made of weft yarn (polyester) and warp yarn (polyester / rayon), and is a warp-warp double weave consisting of two layers, a surface layer and a back layer. In order to reduce the shedding of the cut pile, an acrylic emulsion is permeated into the ground yarn part of the base fabric from the back side. By using hollow and porous fibers, the surface area of ​​the pile is increased compared to that of a fabric using straight fibers of the same fiber diameter.

[0045] The pile in the G-type pile fabric is a crimp pile like the C-type, but half of the pile rows are crimp pile made of C-type hollow and porous fibers, and the other half are crimp pile made of normal fibers that are not hollow or porous. There are two types of raised pile fibers, and each type of pile fiber is alternately fixed to the weft yarn of the ground yarn part that forms the base fabric. The first row of pile is a blend of 3.0 denier Biosafe, 1.5 denier Aqualon, and 1.5 denier rayon, and the second row of pile is a blend of 3.0 denier bulky, 3.0 denier regular, and 1.5 denier rayon. The fiber density is 276,675. The ground yarn part of the base fabric that holds the pile in place is woven with weft yarn (polyester) and warp yarn (polyester / rayon), and is a warp and weft double weave consisting of a surface layer and a back layer. To reduce shedding of the cut pile, an acrylic emulsion is permeated into the ground yarn part of the base fabric from the back side. By comparing the G type pile fabric with the C type pile fabric, we confirmed the extent to which making the fibers used for the pile hollow and porous contributes to grease retention and grease supply.

[0046] The pile fibers in T-type pile fabrics are crimped piles made of multifilaments with irregular cross-section filaments with a split outer periphery, like a *. It has the highest density among the selected pile woven and knitted fabrics. Although it is complicated and expensive because the fibers are split, it has a higher surface area than those using hollow or porous fibers, so it has a higher grease retention and supply capacity.

[0047] The pile length of each of the above types of pile used in the test was 3.3 mm.

[0048] The pile in the B type pile knit fabric is made of normal fibers and has crimping properties. Due to the nature of the knitting, the pile length cannot be made long, and the pile is thinner than the other P type, C type, G type and T type pile fabrics. The pile length of the pile used in the test is 2.3 mm.

[0049] About Felt In order to evaluate the grease retention and sealing properties of woven and knitted pile fabrics in wet end seal materials for linear motion mechanisms, a felt with a thickness similar to that of the evaluation pile (polyester felt, 3 mm thick, density 0.2 g / cm3) was used to compare with the evaluation pile. 2 , heat resistant temperature 0~120℃) is used.

[0050] About grease Lithium grease (consistency No.1 to No.3) was used for the evaluation of pile and felt of each type of pile. In addition, to evaluate pile of type C, molybdenum compound-containing grease (Mo-based) of consistency No.2, urea-based grease (urea-based) of consistency No.2, and fluorine oil for comparison were used.

[0051] - Grease retention evaluation method The grease retention of each of the above woven and knitted pile fabrics is evaluated by the following evaluation method: Evaluation samples are prepared according to the following procedure.

[0052] The selected evaluation pile is cut into two pieces measuring 1 cm square. The two cut evaluation pile pieces are attached to a 200 mm x 30 mm square metal plate that will serve as a measurement terminal using double-sided tape, with the distance between the centers of each pile being 150 mm, and the dry weight (dry weight) before the application of the grease is measured. The above-mentioned grease is applied to the attached evaluation pile using a grease gun up to the maximum amount of impregnation, and the weight (weight after application) is measured. The maximum amount of impregnation is determined visually. The weight after application - dry weight is recorded as the amount of grease applied.

[0053] An evaluation machine is prepared by placing an aluminum disk of about 200 mm in diameter on a rotating table whose rotation speed can be set as desired. The metal plate that serves as the measurement terminal to which the two pieces of evaluation piles coated with the above-mentioned grease are attached is placed so that the midpoint of the two pieces of evaluation piles is aligned with the center of rotation of the aluminum disk of about 200 mm in diameter, and the evaluation piles are brought into contact with the aluminum disk of about 200 mm in diameter, with the piles facing downward. A load of 30 N in total is applied from above the metal plate that serves as the measurement terminal to the two measurement terminals to which the evaluation piles are attached, while the evaluation machine's rotating table is rotated for five minutes at a sliding speed of 500 mm / sec.

[0054] After stopping the rotation, remove the metal plate that serves as the measurement terminal to which the two evaluation piles coated with the grease are attached, and measure its weight (weight after sliding). The weight after coating - weight after sliding is recorded as the amount of applied grease that has flowed out.

[0055] Further, evaluation is performed in the same manner as above, except that felt is used instead of the evaluation pile and lithium stearate grease (consistency No. 2) is used.

[0056] <Result> The evaluation results are shown in Tables 2-1 and 2-2 below.

[0057] [Table 2-1]

[0058] [Table 2-2]

[0059] From the results shown in these tables, the following was found regarding grease retention and grease supply properties:

[0060] The maximum amount of grease that could be absorbed varied depending on the characteristics of the pile used. And, even though the pile with crimping had a larger surface area and lower density, it had a higher maximum amount of grease that could be absorbed and was able to retain a larger amount of grease within the pile. It can be seen that the crimped pile has a higher grease retention than the straight pile.

[0061] In addition, the maximum amount of grease impregnation between fibers having crimping properties differed depending on the pile density. When fibers having crimping properties are used, the surface area increases as the pile density increases, and the maximum amount of grease impregnation increases, allowing a larger amount of grease to be retained within the pile. It can be seen that when fibers having crimping properties are used, a higher pile density has a higher grease retention capacity than a lower pile density.

[0062] The amount of grease that flowed out also differed depending on the characteristics of the pile used. It was also found that piles using fibers with crimping properties had a greater amount of grease that flowed out than piles using straight fibers. It can be seen that straight piles have a larger amount of grease that flows out in a shorter time than crimped piles, resulting in an excessive amount of grease supply and a shorter time during which grease can be supplied.

[0063] The straight pile type P had a small surface area and could not retain grease, resulting in the largest amount of grease leakage. On the other hand, the crimped pile types C and G used hollow porous fibers for some or all of the fibers, and were further crimped, which increased the surface area and increased the amount of grease they could retain. The results of the crimped pile type C showed that it showed the same characteristics in terms of grease retention and grease supply, not only when lithium-based grease was used, but also when urea-based grease and molybdenum-based grease were used. On the other hand, the pile thickness of type B was thin, the impregnation limit was small, and despite the low density, there was no tendency for the amount of leakage to increase dramatically compared to other crimped types.

[0064] From the above, it has become clear that by using hollow porous fibers in the piles used in wet end sealants for linear motion mechanisms to increase the surface area, it is possible to increase the amount of grease retained in the piles and make it more difficult for the retained grease to leak out, thereby preventing excessive grease supply and ensuring a longer grease supply time.

[0065] In actual use, since it is difficult to replenish grease into the piles of the wet end seal material for the linear motion mechanism during use and since it will be used continuously for a longer period of time, it is preferable to use the C type or T type, which have a smaller amount of grease leakage in a given period of time and can supply grease continuously for a longer period of time.

[0066] On the other hand, when fluorine oil is used, its viscosity is significantly lower than the lithium grease, molybdenum compound-containing grease, and urea-based grease, so the maximum amount of oil that can be impregnated is 340 mg, which is more than four times the amount, but the amount of fluorine oil that flows out is large, with more than 60% of the amount impregnated flowing out, and the amount of oil remaining in the pile being less than 40%. Therefore, compared to the lithium grease, molybdenum compound-containing grease, and urea-based grease, the amount of oil that remains in the pile is small, which causes problems with durability. In addition, there is a concern that the low-viscosity fluorine oil will leak into the linear motion mechanism and mix with other lubricants, reducing the expected performance or causing malfunctions.

[0067] <Test Example 2: Confirmation of sealing performance in wet end seal unit for linear motion mechanism>

[0068] Materials and Methods

[0069] Evaluation method Sealing materials are attached to both ends of the linear guide, and the sealing performance is measured after sliding at a specified speed for a specified time.

[0070] The pile used is the same as that used in Test Example 1. Furthermore, for comparison purposes, tests are conducted using a current product using end seals with nips made of an elastomer material and the same felt used in Test Example 1 instead of the pile.

[0071] A pile with a width of 5 mm, molded to the outer periphery of the linear guide, was attached to the plate attached to the end of the linear guide, and lithium stearate grease (consistency No. 2) was applied as the grease. The amount of grease applied to the pile was 4 mg / cm. 2 The sealant is applied in the manner described above to prepare a sample for evaluation. For the C-type pile, the fluorine oil used in Test Example 1 is also applied instead of the lithium stearate grease (consistency No. 2).

[0072] The pile is bent and abutted against the seal materials prepared at both ends of the linear guide so that the gap between the rail and the pile support frame is 2.0 mm thick. Furthermore, paper dust is sealed in a box between the seal materials provided at both ends of the linear guide and the rail, and the box is set. For the C-type pile, a box containing toner instead of paper dust is similarly prepared and set.

[0073] Thereafter, in order to investigate the sealing ability of the sealing material against paper powder or toner, the linear guide is slid at a maximum speed of 400 mm / sec for a maximum evaluation time of 24 hours, so that the linear guide is continuously driven, and the leakage of paper powder or toner and the degree of penetration of the paper powder or toner into the pile of the sealing material are confirmed.

[0074] The test is stopped when the paper dust or toner has leaked through the 5mm wide pile. If the paper dust or toner does not leak out, the amount of paper dust or toner that has penetrated into the fibers of the wet pile that makes up the sealant is measured and the sealability is evaluated. If the amount of penetration exceeds 5mm and the paper dust or toner has leaked out, it is recorded as having leaked to an extent that it is not practical to use (this is indicated as x in the table).

[0075] <Result> The evaluation results are shown in Tables 3-1 and 3-2 below.

[0076] [Table 3-1]

[0077] [Table 3-2]

[0078] When grease was not applied to the pile, paper dust or toner leaked out through the 5 mm wide pile under all conditions. On the other hand, when grease was applied to the pile, it was confirmed that no paper dust leakage occurred even after 24 hours of continuous sliding, which shows that the sealing performance of paper dust provided by applying grease to the pile is extremely high.

[0079] It was also found that the sealing performance differs depending on the characteristics of the pile used, with straight pile having a lower sealing performance and a greater degree of penetration into the pile than crimped pile. It is believed that straight pile pile has no crimping properties, which creates gaps between the fibers and makes it more likely for paper powder to leak. In order to ensure sealing performance with straight pile pile, it is possible to narrow the gap between the guide rail of the linear guide and the sealing material. However, this has the disadvantage of increasing sliding resistance.

[0080] It was found that the sealing ability of sealants using crimped pile differs depending on the type of pile used. With the G type, when the gap width was widened to 2.3 mm, the amount of paper powder that penetrated into the pile increased, causing paper powder leakage. Since the G type has less grease retention than the C and T types, some parts were incompletely sealed, which is thought to have resulted in paper powder leakage. With the C type that retains grease and a gap width of 1.5 mm, it exhibited similarly good sealing ability for both paper powder and toner. On the other hand, the T type has a high density, so the amount of paper powder that penetrates into the pile is low under all conditions.

[0081] Regarding pile bite, the cut pile tip is bent to close the gap between the rail and the support frame, abuts against the rail, and bites into the rail, which tends to have a higher sealing effect overall. In particular, in types C and G, the pile bite has a large sealing effect. However, when the gap width is set to 2.3 mm so that only the pile tip is bitten, the sealing effect does not improve and the effect is weak. It was also found that it is possible to improve the sealing effect even with low-density pile by firmly biting the gap width to 1.5 mm to 2.0 mm. In type B, the pile thickness is thin due to its structure, so the gap width was narrowed to 1.5 mm, and sufficient sealing was not achieved in this test, but it is understood that if the gap width is narrowed further, the sealing effect can be expected to be improved.

[0082] On the other hand, with the current end seal, paper dust leaks out from the surface, making it impossible to seal.

[0083] In addition, when felt is used, the rebound load increases more quickly compared to pile, and the area that can be used as the gap width is narrow, making it difficult to adjust the installation, and even if it is installed, it becomes clear that this will lead to an increase in torque (Fig. 3).In terms of sealing performance, leakage occurs from the corners of the felt, making it clear that it is not suitable as a sealing material.

[0084] From the above, it became clear that from the viewpoint of sealing ability, crimped type fibers have a higher sealing ability, and the sealing ability can be supplemented by the bite, making it possible to create a cheaper sealing material.

[0085] <Test Example 3: Confirmation of sliding resistance in wet end seal unit for linear motion mechanism>

[0086] Materials and Methods

[0087] Evaluation method Sealing materials are attached to both ends of the linear guide, and the resistance value is measured after sliding at a specified speed for a specified time.

[0088] The pile used was the same as that used in Test Example 1. A pile with a width of 5 mm molded to the outer periphery of the linear guide was attached to a plate attached to the end of the linear guide, and lithium stearate grease (consistency No. 2) was used as the applied grease. The amount of grease applied to the pile was 4 mg / cm2. 2 Then, the piles were bent and brought into contact with the sealing materials prepared on both ends of the linear guide so that the gap between the rail and the pile support frame was 2.0 mm in thickness, to close the gap between the rail and the pile support frame.

[0089] Thereafter, the linear guide is allowed to move continuously at a maximum speed of 400 mm / sec and an evaluation time of 30 minutes, after which it is stopped. The linear guide is pressed with the force gauge terminal to measure the value of the sliding resistance.

[0090] <Result> The evaluation results are shown in Table 4 below.

[0091] [Table 4]

[0092] From the results shown in these tables, the following was found regarding the sliding resistance in the end seal material for the linear motion mechanism.

[0093] As a general trend, it became clear that when the piles were impregnated with grease to be used as wet end sealants, the sliding resistance was lower than when the piles were not impregnated with grease. It was also made clear that the sealing performance was improved by pressing the piles against the linear guide rail and biting into it, but on the other hand, the sliding resistance increased.

[0094] The end seal material for the linear motion mechanism, which uses straight P-type pile, has low resistance to the linear guide rail because it uses straight fibers, resulting in low sliding resistance.

[0095] The end seals for linear motion mechanisms using crimped type C and type G pile had similar sliding resistance, probably because the fiber morphology is similar, but the sliding resistance of the G type was slightly lower due to the difference in density.

[0096] The T-type, which is a crimped type, uses fibers with crimping properties, which are made of split *-shaped irregular cross-section fibers.The irregular cross-section has a large surface area and high density, which gives it good sealing properties, but because of its high density, it has higher sliding resistance than other filament shapes.

[0097] Type B is a knitted fabric with a thin base fabric, and because the pile thickness is 2.3 mm and the gap is 2.0 mm, the pile yarn only slightly penetrates the linear guide rail. Therefore, the sliding resistance was low overall.

[0098] For comparison, similar tests were also conducted on the current end seals, simulating actual use, with grease only, and the evaluation was performed. However, because the current end seals are made of an elastomer material, the resistance from the lip was large, and the sliding resistance was greater than when piles were used.

[0099] From the above, it can be seen that a high sliding resistance is effective in improving sealing properties, but from the results of the test examples using C-type and G-type piles, it can be seen that by having the piles bite into the linear guide rail, sufficient sealing properties can be ensured even with low sliding resistance.

[0100] <Test Example 4: Confirmation of sealing ability against curved surfaces> From the results of each of the above test examples 1, it was found that an end sealing material made of wet cut pile in which grease has already been held between the pile fibers of the cut pile can ensure sufficient sealing performance extremely effectively even with low sliding resistance, by bending the tips of the cut pile, which have grease already held between the pile fibers, to abut against the rail so as to seal the gap between the rail and the support frame.

[0101] In most linear motion mechanisms, the gap to be filled is composed of a smooth surface, but in order to confirm whether it is possible to ensure sufficient sealing extremely effectively even if the gap to be filled has a curved surface, even if the sliding resistance is similarly low, a ball screw, whose gap shape is composed of a more complex curved surface, was used as an example of a gap to be filled with a curved surface, and tests were carried out to confirm whether the present invention would be able to ensure sufficient sealing by bending the tips of the cut pile, which has grease already held between the pile fibers, along the ball screw so as to close the gap, just as in the case of using it in a linear motion mechanism where the gap to be filled is composed of a smooth surface.

[0102] Materials and Methods

[0103] Evaluation method A sealant is attached to the end of a ball screw, and the sealing performance after sliding at a specified speed for a specified time is evaluated based on the amount and distribution of toner remaining on the rail groove surface of the ball screw.

[0104] The present invention provides a ball screw in which an externally threaded shaft having a continuous arc-shaped groove and a nut portion are screwed together via a number of steel balls inserted between the external and internal threads, with the nut being fed back and forth on the externally threaded shaft; an end seal material in which C-type piles are spirally arranged around the inner periphery of a support frame so that the outer periphery of the externally threaded shaft attached to the front or rear of the nut portion of the ball screw faces the groove portion over a length of at least one rotation; and C-type piles for spirally arranging the piles around the inner periphery of the support frame so that the outer periphery of the screw shaft faces the groove portion over a length of at least one rotation, with the same pitch as the groove portion of the ball screw.

[0105] A C-type pile is disposed on the inner periphery of the support frame so as to face the groove portion over a length of at least one revolution of the outer periphery of the screw shaft. Lithium stearate grease (consistency No. 2) is applied to the C-type pile as a coating grease, and the amount of grease applied to the pile is 4 mg / cm. 2 A plate is then snap-fitted and fixed to the insertion end surface to prevent the pile from slipping out, to form an end seal material that serves as an evaluation sample, which is then attached to the front or rear of the ball screw nut.

[0106] After that, toner (particle size: 5 μm) is sprinkled into the groove of the ball screw, and the ball screw is manually moved back and forth 10 times before being stopped. The amount and distribution of toner remaining on the surface of the rail groove of the ball screw is confirmed.

[0107] In addition, for comparison, a test was conducted using the same procedures, except that a brush seal molded into a ring shape for a current ball screw was used instead of the end seal material of the evaluation sample, and the amount and distribution of toner remaining on the surface of the rail groove of the ball screw was confirmed.

[0108] <Result> As a result of the evaluation, it was confirmed that when an end sealing material using the wet pile of the present invention is used, even when the surface to be sealed is composed of a roughly curved surface such as the groove of a ball screw, surprisingly, no fine toner powder remains in various places, the sealing performance of the groove which forms the valley of the ball screw is sufficiently ensured, and it is believed that no toner has entered the bearing, which is the rolling body.

[0109] In the present invention, the pile bristles are bent to contact the ball screw, particularly the valley of the ball screw, and can be arranged in a spiral shape to contact the rolling element, the bearing, and as a result, the pile and its bristles sweep out fine toner particles, while the lubricant held in advance between the pile fibers prevents the intrusion of fine toner particles, providing an effective seal that could not be achieved with conventional techniques. It is understood that in ball screws of various shapes, the pile material used in the present invention follows the ball screw, uniformly contacts it without any contact leakage, and further, the use of the lubricant held in advance between the pile fibers provides a sweeping effect and a sealing effect against fine particles such as toner.

[0110] In contrast, it was confirmed that with the current brush seal, fine toner powder remained in bands in various places on the ball screw, especially in the valleys where the rolling element, the bearing, abuts, and that toner lumps remained in places. It was found that the current brush seal, a conventional product, was not able to ensure sealing performance in the valleys of the ball screw, and that toner was getting onto the rolling element, the bearing.

[0111] The current brush seal is a ring-shaped brush, and since the brush does not contact the ball screw evenly, it is believed that there will be some areas where the brush does not touch. Therefore, a detailed observation was made of the state of contact between the current brush seal and the ball screw, and it was confirmed that there are some areas where the brush is bent due to the difference in height between the root and crest of the ball screw, and does not contact the root at all. With the current brush seal, it is found that when the surface to be sealed is composed of a curved surface such as the groove of a ball screw, it is difficult to seal the surface from foreign matter. [Explanation of symbols]

[0112] 1. A support frame arranged on the outer periphery of the male screw shaft of the divided ball screw 2. A wet seal containing grease that is arranged opposite the spiral groove of the ball screw. 3. A plate fixed to a support frame arranged on the outer periphery of the male screw shaft of a ball screw to prevent the wet seal material containing grease arranged opposite the spiral groove of the ball screw from coming off. 4. A support frame arranged on the outer periphery of the male screw shaft of the ball screw 5. A wet seal member containing grease, the piles of which are cut into stripes along the spiral groove of the ball screw so as to face the spiral groove of the ball screw. 6 Linear guide 7 Rail 8 Slider 9 End seal 10 Cut pile 11 Support frame 12 Base fabric part 13 Screw 14 Exterior body

Claims

1. An end seal material to be attached to both ends of a slider of a linear motion mechanism consisting of a rail and a slider, The end seal material is A support frame disposed on the outer periphery of the rail; A base fabric portion having a back surface fixed to an inner peripheral surface of the support frame; The fabric has cut pile protruding from the surface of the base fabric, The tips of the cut pile are bent to close the gap between the rail and the inner periphery of the support frame and come into contact with the rail, and the bent tips are engaged in the gap between the rail and the inner periphery of the support frame, A lubricant is held between the pile fibers of the cut pile in advance. An edge sealant made of wet cut pile, characterized by:

2. 2. The end seal material according to claim 1, wherein the lubricant held between the pile fibers of the cut pile is a grease having a consistency number of 1 to 4 according to JIS K2220.

3. 3. The end seal material according to claim 2, wherein the grease is any one of lithium grease, grease containing a molybdenum compound, and urea-based grease.

4. 4. The edge seal material according to claim 1, wherein the cut pile has a pile length of 2 mm or more.

5. 5. The edge seal material according to claim 1, wherein the pile fibers of the cut pile are made of crimped multifilament fibers.

6. 6. The edge seal material according to claim 1, wherein the cut pile is made of a woven fabric.

7. 6. The edge seal material according to claim 1, wherein the cut pile is made of knitted fabric.

8. 8. A linear motion mechanism comprising a rail and a slider, the end seal material according to claim 1 being detachably and replaceably fixed to both ends of the slider.

Images