Linear motion guide device

Abstract

To provide a linear motion guide device which inhibits deterioration of a function of a side seal and reduces a replacement frequency to achieve reduction of running costs.SOLUTION: A linear motion guide device includes: a guide rail; a slider which is disposed so as to move relative to the guide rail in an axial direction; a plurality of rolling elements which is disposed so as to be rollable along the inside of a rolling element rolling passage formed between the guide rail and the slider; and side seals each of which is attached to an end in a moving direction of the slider. The side seal includes: a seal part which contacts with the guide rail; a biasing device which biases the seal part in a biasing direction toward the guide rail; and a guide part which guides the seal part in a manner that enables the seal part to be displaced along the biasing direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a linear guide device. [Background technology]

[0002] Linear guiding devices use contact seals such as side seals, inner seals, under seals, and bottom seals. For example, Patent Document 1 discloses a technology for a linear guiding device equipped with a side seal attached to the axial end of a slider with a predetermined interference with a guide rail, in which the interference δ1 of the side seal with respect to the center of the upper surface of the guide rail is made larger than the interference δ2 with respect to the side surface of the guide rail. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-170280 A Summary of the Invention [Problem to be solved by the invention]

[0004] The side seal is a seal that seals the gap between the guide rail and the end cap to prevent foreign objects from entering from the outside and to prevent lubricating oil from leaking. Therefore, the side seal wears out due to sliding with the guide rail over a long period of time in response to the operation of the linear guide device, which reduces the sealing function. For this reason, it is necessary to perform regular inspections and replace worn side seals, which increases the running costs of the linear guide device.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a linear guide device that can reduce running costs by suppressing deterioration of the functionality of the side seals and reducing the frequency of their replacement. [Means for solving the problem]

[0006] The linear guide device of the present invention is Guide rails and a slider arranged to move relative to the guide rail in an axial direction; a plurality of rolling elements arranged to roll along a rolling element rolling path formed between the guide rail and the slider; a side seal attached to an end of the slider in a moving direction, The side seal is characterized in having a seal portion that abuts against the guide rail, a biasing device that biases the seal portion in a biasing direction toward the guide rail, and a guide portion that guides the seal portion so that it can be displaced along the biasing direction. Effect of the Invention

[0007] According to the present invention, it is possible to provide a linear guide device that can reduce running costs by suppressing deterioration of the function of the side seal and reducing the frequency of replacement thereof. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a linear guide device according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view of a slider of the linear guide device shown in FIG. [Diagram 3] 3(a) is a view of the side seal case seen from the AA surface in FIG. 2 in the direction of the arrow, and FIG. 3(b) is a view of the case in FIG. 3(a) cut along the BB cross section and seen in the direction of the arrow. [Figure 4] FIG. 4 is a front view of the slider as viewed along the longitudinal direction. [Diagram 5] FIG. 5 is a front view of the slider illustrating the process of assembling the side seal. [Figure 6] FIG. 6 is a front view of the slider illustrating the process of assembling the side seal. [Figure 7] FIG. 7 is a front view of the slider illustrating the process of assembling the side seal. [Figure 8]FIG. 8 is a front view of the slider according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] (First embodiment) Fig. 1 is a perspective view of a linear guide device 11 according to a first embodiment, and Fig. 2 is a perspective view of a slider 15 of the linear guide device 11 shown in Fig. 1. In Figs. 1 and 2, a grease nipple is removed, and in Fig. 2, a screw 53 is removed. In an XYZ orthogonal coordinate system perpendicular to each other, the X-axis direction is the width direction of the guide rail 13, the Y-axis direction is the longitudinal direction of the guide rail 13, and the Z-axis direction is the height direction of the guide rail 13 and the slider 15.

[0011] The linear guide device 11 according to this embodiment has a guide rail 13, a slider 15 that moves relative to the guide rail 13, rolling elements and a cage (not shown), and a seal member that closes the gap between the guide rail 13 and the slider 15. The multiple rolling elements are arranged to roll freely along a rolling element rolling path formed between the guide rail 13 and the slider 15, thereby allowing the slider 15 to move axially relative to the guide rail 13.

[0012] Here, the seal member is a general term for the side seal 41 attached to the end of the slider 15 in the moving direction, and a bottom seal, an under seal, and an inner seal (not shown).

[0013] A pair of guide rail side raceway surfaces (rolling element raceway surfaces) 19 are formed on the side surface of the guide rail 13 along the longitudinal direction of the guide rail 13. The slider 15 includes a slider body 21 and a pair of end caps 23 provided on both ends of the slider body 21 in the moving direction (longitudinal direction).

[0014] In the slider 15 , side seals 41 are arranged on both sides of the end cap 23 in the longitudinal direction, and the side seals 41 are fixed to the end cap 23 by screws 53 .

[0015] The slider body 21, end cap 23, and side seal 41 all have a U-shaped cross section and are installed to straddle the guide rail 13. That is, the slider body 21, end cap 23, and side seal 41 have a recessed groove formed in the center to accommodate the guide rail 13.

[0016] Fig. 3(a) is a view of the case 43 of the side seal 41 as viewed in the direction of the arrow from the AA plane in Fig. 2, and Fig. 3(b) is a view of the case 43 of Fig. 3(a) cut along the BB cross section as viewed in the direction of the arrow, with the actual parts shown hatched for ease of understanding. Fig. 4 is a front view of the slider 15 as viewed along the longitudinal direction, with the internal structure shown by dotted lines. Figs. 5 to 7 are front views showing the assembly process of the side seal 41. Here, only one side seal 41 will be described, but the other side seal 41 is similar, so repeated description will be omitted.

[0017] The side seal 41 consists of an end plate 42 (see Figure 2), a metal case 43 (see Figure 3) held between the end plate 42 and the end cap 23, and a first seal portion 44, a second seal portion 45, and a third seal portion 46 (see Figure 4) respectively attached to the case 43.

[0018] The thin, flat end plate 42 has approximately the same shape as the end cap 23 when viewed from the front side as shown in Figure 4, and has a hole 42a (Figures 1 and 2) for attaching the grease nipple GN and a hole (not shown) for inserting the screw 53.

[0019] Meanwhile, case 43, which has a uniform plate thickness, is also formed in a U-shape, and the upper edge and side edges of case 43 coincide with those of end cap 23. The height of case 43 also coincides with the height of end cap 23. Therefore, when case 43 is held between end plate 42 and end cap 23, there are no gaps at the upper edge and side edges, making it difficult for foreign objects to enter.

[0020] However, the inner upper edge 43a of the case 43 is located higher in the Z-axis direction than the inner upper edge 42b of the end plate 42, and the inner side edge 43b of the case 43 is located outward in the X-axis direction than the inner side edge 42c of the end plate 42. Therefore, when the case 43 is held between the end plate 42 and the end cap 23, the inner upper edge 43a of the case 43 is pulled upward in the Z-axis direction from the inner upper edge 42b of the end plate 42 (and the end cap 23), and the inner side edge 43b of the case 43 is pulled on both sides of the X-axis from the inner side edge 42c of the end plate 42 (and the end cap 23). In other words, a U-shaped mounting groove is formed between the end plate 42 and the end cap 23, with the inner upper edge 43a and the inner side edge 43b of the case 43 as bottoms.

[0021] One surface of the case 43 in the Y-axis direction (the right surface in FIG. 3(b), the back surface) is flat except for the through holes, and the other surface (the left surface in FIG. 3(b), the front surface) has grooves and recesses. With reference to FIGS. 3 and 5, a pair of first straight grooves 43c, 43c is formed in the inner upper edge 43a of the case 43 in the shape of a long and narrow dead end along the Z-axis direction. Since the surface of the case 43 is shielded by the end plate 42, the openings in the Y-axis direction of the first straight grooves 43c, 43c are each shielded, and the upper portion in the Z-axis direction is also shielded, so that a blind hole-like space is formed in the first straight grooves 43c, 43c. The space in the first straight grooves 43c, 43c that is open only downward in the Z-axis direction is called a first guideway. The first guideway and the first guide pin 44c that is slidable along the first guideway constitute a guide section.

[0022] In addition, a U-shaped groove 43d, which also serves as a recess, is formed on the inner upper edge 43a between the first straight grooves 43c, 43c. Since the surface of the case 43 is shielded by the end plate 42, a space that is open only downward in the Z-axis direction is also formed in the U-shaped groove 43d. The space in the U-shaped groove 43d that is open only downward in the Z-axis direction is called a first pocket. A first biasing member 47 made of elastically deformable rubber or resin is housed in the center of the U-shaped groove 43d, and in a free state (see FIG. 5), its lower end protrudes downward in the Z-axis direction from the inner upper edge 43a.

[0023] In addition, the second straight grooves 43e, 43e are formed in the inner side edges 43b, 43b on both sides of the case 43 in the shape of an elongated dead end facing each other along the X direction. Since the surface of the case 43 is shielded by the end plate 42, the open parts in the Y direction of the second straight grooves 43e, 43e are shielded, and the outer ends in the X direction are also shielded, so that a blind hole-like space is formed in the second straight grooves 43e, 43e. The space in the second straight groove 43e in which only the inner right end in the X direction is open is called the second guideway, and the space in the second straight groove 43e in which only the inner left end in the X direction is open is called the third guideway. It is preferable that the axes of the second guideway and the third guideway coincide with each other, and the axis of the first guideway is perpendicular to the axis of the second guideway and the third guideway. The second guide path, the third guide path, and the second guide pin 45d and the third guide pin 46d slidable relative to the second guide path and the third guide path constitute a guide portion.

[0024] In addition, adjacent to the second linear grooves 43e, 43e, rectangular grooves 43f, 43f are formed on the inner side edge 43b. The surface of the case 43 is shielded by the end plate 42, so that a space is formed in the rectangular grooves 43f, 43f whose left end or right end in the X-axis direction is shielded. The spaces in the rectangular grooves 43f, 43f whose only inner end in the X-axis direction is open are called the second pocket portion and the third pocket portion. The rectangular grooves 43f, 43f respectively house the second and third urging members 48 and 49 made of elastically deformable rubber or resin, and in a free state (see FIG. 5), their lower ends protrude inward in the X-axis direction from the inner side edge 43b. The case 43, the first urging member 47, the second urging member 48, and the third urging member 49 constitute an urging device.

[0025] 3, case 43 has a through opening 43g so as not to interfere with the injection path connected to grease nipple GN (FIG. 4). Also, through holes 43j for inserting screws 53 and recesses 43h and 43i, which also serve to reduce the thickness of case 43, which is made of resin, are formed on both sides of case 43.

[0026] 5, the first seal portion 44 has an elongated main body portion 44a extending in the X-axis direction, oblique side portions 44b, 44b connected to both longitudinal ends of the main body portion 44a and extending diagonally downward, and two first guide pins 44c, 44c extending in the Z-axis direction from the upper surface of the main body portion 44a. The main body portion 44a and the oblique side portions 44b, 44b are made of a resin plate, and the first guide pins 44c, 44c are made of metal. The first seal portion 44 is preferably formed by, for example, insert molding.

[0027] The plate-like second seal portion 45 has a rectangular main body portion 45a extending in the Z-axis direction, a semicircular portion 45b formed so as to protrude rightward in the X-axis direction from near the center of the main body portion 45a, a convex portion 45c formed so as to protrude rightward in the X-axis direction from the apex of the semicircular portion 45b in the X-axis direction, and a second guide pin 45d implanted so as to protrude leftward from the main body portion 45a and extend in the X-axis direction. The main body portion 45a, the semicircular portion 45b, and the convex portion 45c are made of resin plates, and the second guide pin 45d is made of metal. The second seal portion 45 is preferably formed by, for example, insert molding.

[0028] The plate-shaped third seal portion 46 has a rectangular main body portion 46a extending in the Z-axis direction, a semicircular portion 46b formed so as to protrude leftward in the X-axis direction from near the center of the main body portion 46a, a convex portion 46c formed so as to protrude leftward in the X-axis direction from the apex of the semicircular portion 46b in the X-axis direction, and a third guide pin 46d implanted so as to protrude rightward from the main body portion 46a and extend in the X-axis direction. The main body portion 46a, the semicircular portion 46b, and the convex portion 46c are made of resin plates, and the third guide pin 46d is made of metal. The third seal portion 46 is preferably formed by, for example, insert molding.

[0029] Next, the process of assembling the side seal 41 will be described. With the end cap 23, the case 43, and the end plate 42 fixed to the slider body 21 using the screws 53, the slider body 21 is turned upside down from the state shown in Fig. 5. From this state, as shown by the arrow in Fig. 5, the first seal portion 44 is moved toward the inner upper edge 43a of the case 43, the first guide pins 44c, 44c are inserted into the first linear grooves 43c, 43c, and the first biasing member 47 is pressed and compressed while being pushed into the mounting groove formed between the case 43 and the end plate 42 along the Z-axis direction. At this time, the inner side edge 43b of the case 43 slides and guides both sides of the oblique side portion 44b, so that the first seal portion 44 can be smoothly assembled. When the upper edges of the main body portion 44a and the oblique side portion 44b abut against the inner upper edge 43a of the case 43, the first seal portion 44 is biased in the Z-axis direction (away from the inner upper edge 43a) by the elastic force of the first biasing member 47.

[0030] Next, as shown by the arrow in Figure 6, the second seal portion 45 is moved toward the left inner side edge 43b of the case 43, the second guide pin 45d is inserted into the second straight groove 43e on the left side, and the second biasing member 48 is pressed and compressed while being pushed along the X-axis direction into the mounting groove formed between it and the end plate 42.

[0031] In addition, the third seal portion 46 is brought closer toward the right inner side edge 43b of the case 43, the third guide pin 46d is inserted into the right-side second straight groove 43e, and the third biasing member 49 is pressed and compressed while being pushed along the X-axis direction into the mounting groove formed between it and the end plate 42.

[0032] With the second seal portion 45 and the third seal portion 46 assembled in this manner, the main body portions 45a and 46a of the second seal portion 45 and the third seal portion 46 protrude inward in the X-axis direction from the inner side edge 42c of the end plate 42 (and the end cap 23), and the opposing edges of the oblique side portion 44b of the first seal portion 44 abut against the opposing edges of the second seal portion 45 and the third seal portion 46. Since the second seal portion 45 and the third seal portion 46 can be displaced only in the X-axis direction due to the engagement between the rectangular grooves 43f, 43f and the guide pins 45d, 46d, the second seal portion 45 and the third seal portion 46 can support the biasing force of the first biasing member 47, thereby preventing the first seal portion 44 from slipping out in the Z-axis direction.

[0033] Additionally, the opposing edges of the oblique side portions 44b of the first seal portion 44 abut against the opposing edges of the second seal portion 45 and the third seal portion 46. The side seals 41 are attached to both sides of the slider body 21 in the Y axis direction.

[0034] 7, when the slider 15 with the side seal 41 assembled thereto is attached to the guide rail 13, the lower edges of the main body 44a and the oblique side 44b of the first seal portion 44 come into contact with the upper surface of the guide rail 13, and the inner edges of the main body portions 45a and 46a of the second seal portion 45 and the third seal portion 46 come into contact with the side surface of the guide rail 13, while the semicircular portions 45b and 46b and the convex portions 45c and 46c come into contact with the guide rail side raceway surface 19 without any gaps. This seals the entire upper surface and side surface of the guide rail 13, preventing leakage of lubricating oil and entry of foreign matter. However, when the lower edge of the oblique side portion 44b comes into contact with the upper edges of the main body portions 45a and 46a, elastic deformation occurs in both. In addition, the sealing pressure between the first seal portion 44, the second seal portion 45, and the third seal portion 46 and the guide rail 13 can be adjusted by the biasing force of the first biasing member 47, the second biasing member 48, and the third biasing member 49.

[0035] When the linear guide device 11 is in use, the slider 15 moves back and forth along the guide rail 13, and accordingly, the first seal portion 44, the second seal portion 45 and the third seal portion 46 slide against the guide rail 13, resulting in wear at the sliding portions.

[0036] However, the first seal portion 44 is biased downward in the Z-axis direction (biasing direction) by the biasing force of the first biasing member 47. Therefore, even if the lower edges of the main body portion 44a and the oblique side portion 44b of the first seal portion 44 wear, the main body portion 44a and the oblique side portion 44b are displaced downward in the Z-axis direction by the amount of wear while the first guide pins 44c, 44c are guided by the first linear grooves 43c, 43c, and thus maintain close contact with the guide rail 13, and therefore the sealing function will not be impaired for a long period of time.

[0037] Similarly, the second seal portion 45 and the third seal portion 46 are biased inward (biasing direction) in the X-axis direction by the biasing force of the second biasing member 48 and the third biasing member 49. Therefore, even if the side edges of the main body portions 45a, 46a, the semicircular portions 45b, 46b, and the protruding portions 45c, 46c of the second seal portion 45 and the third seal portion 46 wear, the guide pins 45d, 46d are guided by the second linear grooves 43e, 43e, and displace inward in the X-axis direction by the amount of wear to maintain close contact with the guide rail 13, so that the sealing function is not impaired for a long period of time. Therefore, by suppressing the replacement frequency of the side seal 41, the running cost of the linear guide device 11 can be reduced.

[0038] In this embodiment, a groove is provided on one side of the case 43 to serve as a guide portion or a pocket portion, but instead of the groove, a notch that is open in both Y-axis directions may be formed on the inner edge of the case 43, and the guide portion or the pocket portion may be formed by sandwiching the notch between the end plate 42 and the flat end surface of the end cap 23. Also, it is not necessary to provide the first guide pins 44c, 44c and the first linear grooves 43c, 43c, the guide pins 45d, 46d, and the second linear grooves 43e, 43e. In that case, the second seal portion 45 and the third seal portion 46 can be displaced in the X-axis direction with the lower edge of the first seal portion 44 as a guide portion, and the first seal portion 44 can be displaced in the Z-axis direction with the inner side edge 43b of the case 43 as a guide portion.

[0039] Second Embodiment 8 is a front view of a slider 15A according to the second embodiment. The slider 15A of this embodiment also constitutes a linear guide bearing by being assembled to the above-mentioned guide rail 13. The slider 15A of this embodiment is provided with side seals 41A on both sides in the Y-axis direction.

[0040] The side seal 41A has a pair of generally L-shaped pivot plates 42A, 42A, a biasing member 43A, and a U-shaped integrated seal portion 44A.

[0041] The U-shaped integrated seal portion 44A includes an upper portion 44Aa that contacts the upper surface of the guide rail 13 (see FIG. 1) and side portions 44Ab, 44Ab that contact the side surfaces of the guide rail 13, which are connected together.

[0042] The pivot plates 42A, 42A have circular holes and collars (not shown) through which screws 53 for attaching the pivot plates 42A, 42A to the end cap 23 are inserted, and the pivot plates 42A, 42A are pivotally supported around their axes by inserting the screws 53 into the circular holes and collars. In this embodiment, the positions of the circular holes and collars (screws 53) are displaced downward in the Z direction and outward in the X direction (to a position closer to the upper end of the integral seal portion 44A) compared to the above embodiment. The lower ends 42Aa, 42Aa of the pivot plates 42A, 42A become pressing parts that press the side parts 44Ab, 44Ab of the integral seal portion 44A. In addition, a protrusion 39a that protrudes in the Y direction between the pivot plates 42A, 42A is formed adjacent to the integral seal portion 44A on the side wall 39 of the side seal that extends parallel to the Y-direction end face of the end cap 23.

[0043] The biasing member 43A, which is made of resin or rubber or is a spring, is connected to the upper ends of the pivot plates 42A, 42A and biases the upper ends of the pivot plates 42A, 42A in a direction in which they open (in the direction of the arrow in FIG. 8) by its elastic force. The pivot plates 42A, 42A and the biasing member 43A constitute a biasing device. The rest of the configuration is the same as in the above-mentioned embodiment, so repeated explanations will be omitted.

[0044] The slider 15A to which the side seal 41A is attached can be attached to the guide rail 13 in the same manner as in the above-described embodiment. At this time, the lower edge of the upper portion 44Aa of the integrated seal portion 44A abuts against the upper surface of the guide rail 13, and the inner side edge of the side portion 44Ab abuts against the side surface of the guide rail 13 (including the guide rail side raceway surface 19) without any gap. This seals the entire upper surface and side surface of the guide rail 13, thereby preventing leakage of lubricating oil and entry of foreign matter. The sealing pressure between the integrated seal portion 44A and the guide rail 13 can be adjusted by the biasing force of the biasing member 43A.

[0045] According to this embodiment, the lower end sides of the pivot plates 42A, 42A are biased in a closing direction (biasing direction) by the biasing force of the integral seal portion 44A. Therefore, when wear occurs in the sliding portion of the integral seal portion 44A due to use of the linear guide device 11, the integral seal portion 44A displaces inward in the X-axis direction by the amount of wear and maintains close contact with the guide rail 13, so that the sealing function is not impaired for a long period of time. At this time, the side surface of the integral seal portion 44A is biased by the pivot plates 42A, 42A, so that the center of the integral seal portion 44A tries to deform to have an upward convex shape, but the upper end of the integral seal portion 44A abuts against the convex portion 39a and the displacement is suppressed, thereby ensuring the sealing performance.

[0046] The present invention is not limited to the above-described embodiments, and the present invention also contemplates the mutual combination of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the description in the specification and well-known techniques, and these are included in the scope of protection sought. [Explanation of symbols]

[0047] 11 Linear guide device 13 Guide rail 15,15A slider 19 Guide rail side raceway surface 23 End cap 41,41A Side seal 42 End plate 43 cases 44 First seal part 45 Second seal part 46 Third seal part 47 First biasing member 48 Second biasing member 49 Third biasing member 42A pivot plate 43A Pressurizing member 44A Integrated seal

Claims

1. Guide rails and a slider arranged to move relative to the guide rail in an axial direction; a plurality of rolling elements arranged to roll along a rolling element rolling path formed between the guide rail and the slider; a side seal attached to an end of the slider in a moving direction, the side seal has a seal portion that abuts against the guide rail, a biasing device that biases the seal portion in a biasing direction toward the guide rail, and a guide portion that guides the seal portion so that it can be displaced along the biasing direction.

2. the seal portion includes a first seal portion that contacts an upper surface of the guide rail, and a second seal portion and a third seal portion that contact side surfaces of the guide rail; the biasing device includes a case attached to the slider, a first biasing member disposed in a first pocket of the case and biasing the first seal portion toward the guide rail, a second biasing member disposed in a second pocket of the case and biasing the second seal portion toward the guide rail, and a third biasing member disposed in a third pocket of the case and biasing the third seal portion toward the guide rail, 2. The linear guide device according to claim 1, wherein the first seal portion, the second seal portion, and the third seal portion are separate bodies.

3. The linear guide device according to claim 2 , wherein the biasing force transmitted from the first biasing member via the first seal portion is supported by at least one of the second seal portion and the third seal portion.

4. the guide portion includes a first guide pin formed in the first seal portion and slidable relative to a first guide path of the case, a second guide pin formed in the second seal portion and slidable relative to a second guide path of the case, and a third guide pin formed in the third seal portion and slidable relative to a third guide path of the case, 4. The linear guide device according to claim 2, wherein the first guideway is perpendicular to an axis of the second guideway and an axis of the third guideway.

5. The seal portion is an integrated seal portion having an upper portion that contacts an upper surface of the guide rail and a side portion that contacts a side surface of the guide rail, 2. The linear guide device according to claim 1, wherein the biasing device comprises: a pivot plate that is pivotable with respect to the slider and has a pressing portion that is arranged with the integrated seal portion sandwiched between the pivot plate and the guide rail; and a biasing member that biases the pressing portion of the pivot plate so as to pivot toward the guide rail.

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