Crank drive for a weaving machine

Abstract

The present application provides a structure that is difficult to generate a deflection of a drive shaft. A crank drive device of a loom includes a crank hub that is rotatably mounted to a drive shaft, a bracket that is rotatably mounted to the crank hub, an eccentric shaft that is supported by the bracket, and a link member that is rotatably supported by the bracket via the eccentric shaft and a bearing and is linked to a drive target member of the loom, the bracket has a mounted surface that is mounted to the crank hub, the mounted surface is orthogonal to an axis of the drive shaft and is a surface on a front end side of the drive shaft, the crank hub has a mounting portion that is a plate-shaped mounting portion that mounts the mounted surface of the bracket and has a mounting surface that abuts against the mounted surface, and a fixing mechanism that is a fixing mechanism for fixing the crank hub to the drive shaft and is fitted into the drive shaft, in the crank drive device of the loom, the crank hub is configured such that the fixing mechanism is located on the mounting surface side in a plate thickness direction of the mounting portion.

Description

Technical Field

[0001] This invention relates to a crank-type drive device for a loom, comprising a crank hub non-rotatably mounted to a drive shaft, a bracket non-rotatably mounted to the crank hub, an eccentric shaft supported by the bracket, and a connecting member rotatably supported by the bracket and connected to a drive component of the loom via the eccentric shaft and bearings. Specifically, in the aforementioned crank-type drive device, the bracket has a mounting surface mounted on the crank hub, which is orthogonal to the axis of the drive shaft and is the front end side of the drive shaft. The crank hub has: a mounting portion, which is a plate-shaped mounting portion for mounting the mounting surface of the bracket and has a mounting surface abutting against the mounting surface; and a fixing mechanism, which is a fixing mechanism for fixing the crank hub to the drive shaft and is fitted into the drive shaft. Background Technology

[0002] In a loom, warp yarns fed from the warp feed beam are wound onto a tension roller and guided toward the weft. Furthermore, to mitigate tension fluctuations caused by the shedding movement of the warp yarns, a warp loosening device is used that actively applies a loosening motion to the tension roller during each loom cycle. As the drive unit for this warp loosening device, a drive unit utilizing a crank-type drive is generally used; the device disclosed in Patent Document 1 is an example of such a crank-type drive.

[0003] Furthermore, as a crank-type drive device used in a loom, in addition to the device used in the aforementioned loosening device, there are, for example, the device used in the shedding device of a loom disclosed in Patent Document 2, and the device used in the raising action mechanism of a raising loom disclosed in Patent Document 3.

[0004] Based on this, the crank-type drive device disclosed in Patent Document 1 (hereinafter referred to as the "conventional device") comprises: a crank hub, which is non-rotatably mounted to the drive shaft; a bracket, which is non-rotatably mounted to the crank hub; an eccentric shaft portion supported by the bracket; and a connecting member, which is rotatably supported by the bracket via the eccentric shaft portion and a bearing, and connected to a loosening rod. Furthermore, in this conventional device, the crank hub has an open-end fastening mechanism as a fixing mechanism, and is mounted to the drive shaft by this open-end fastening mechanism. The bracket is mounted such that its mounting surface abuts against the end face of the crank hub that serves as the mounting surface. Moreover, in this mounted state, both the mounting surface and the mounted surface are orthogonal to the axis of the drive shaft.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2008-180289

[0008] Patent Document 2: Japanese Patent Application Publication No. 7-133545

[0009] Patent Document 3: Japanese Patent Application Publication No. 10-331054 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] Furthermore, in existing devices, the crank hub is formed such that, relative to the plate-shaped flange including the aforementioned mounting surface, an open fastening mechanism protrudes from an end face opposite to the mounting surface. Moreover, the crank hub is mounted on the drive shaft with the open fastening mechanism positioned relative to the flange on the front end side of the drive shaft. Therefore, in existing devices configured in this way, problems sometimes arise where the movement of the driven component, caused by the deflection of the drive shaft, becomes a movement different from the desired movement.

[0012] More specifically, taking the use of an existing device in the warp release mechanism of a loom as an example, the drive shaft is supported in a manner that allows it to rotate relative to the loom frame via bearings and protrudes from the loom frame. Furthermore, in the case of the existing device configured as described above, the drive shaft needs to have a length protruding from the loom frame so that at least the flange portion and support of the crank hub can be positioned between the location of the opening fastening mechanism for fixing the crank hub in its axial direction and the loom frame. As a result, in the case of the existing device, the dimension (execution length) from the bearing-supported portion of the drive shaft to the portion fixing the crank hub becomes larger.

[0013] Furthermore, in the aforementioned situation, the existing device is connected to the tension roller via a connecting member or the like. Therefore, the tension of the warp yarn applied to the tension roller is applied to the existing device via this connecting member or the like, resulting in a force being applied to the drive shaft via the support and crank hub. Moreover, this force acts in the direction that causes the drive shaft to deflect, with the portion supported by the aforementioned bearing as a fulcrum. Therefore, if the aforementioned execution length is large, as described above, the drive shaft may deflect. In particular, in looms used for weaving wide-width fabrics, high-density industrial fabrics, etc., the force applied to the drive shaft becomes even greater, potentially leading to significant deflection of the drive shaft.

[0014] Furthermore, if the drive shaft flexes in this way, the relationship between the rotational phase of the drive shaft and the position of the tension roller during the periodic loosening motion will deviate, resulting in the actual movement of the tension roller becoming different from the pre-designed movement (desired movement). In addition, the amount of deviation corresponds to the flexing of the drive shaft, and depending on its magnitude, it may have an adverse effect on weaving, leading to a reduction in the quality of the woven fabric.

[0015] In view of the existing crank-type drive mechanism of the loom described above, the object of the present invention is to provide a structure in which the deflection of the drive shaft, which is the cause of the above-mentioned problems, is difficult to occur in the crank-type drive mechanism of the loom described above.

[0016] Solution for solving the problem

[0017] This invention is based on a crank-type drive device for a loom. The crank-type drive device includes: a crank hub that is non-rotatably mounted on a drive shaft; a bracket that is non-rotatably mounted on the crank hub; an eccentric shaft supported by the bracket; and a connecting member that is rotatably supported by the bracket and connected to a drive component of the loom via the eccentric shaft and bearings. In particular, the bracket has a mounting surface that is mounted on the crank hub, which is orthogonal to the axis of the drive shaft and is the front end side of the drive shaft. The crank hub has: a mounting portion; which is a plate-shaped mounting portion that mounts the mounting surface of the bracket and has a mounting surface that abuts against the mounting surface; and a fixing mechanism that is a fixing mechanism for fixing the crank hub to the drive shaft and is fitted into the drive shaft.

[0018] Furthermore, the present invention is characterized in that the crank hub is configured such that the fixing mechanism is located on the mounting surface side in the plate thickness direction of the mounting portion.

[0019] Furthermore, in such a crank-type drive device for a loom of the present invention, the crank-type drive device may also be configured such that the range of the fixing mechanism in the crank hub and the range of the bearing overlap in the axial direction of the drive shaft.

[0020] The effects of the invention are as follows.

[0021] According to the present invention, in the crank-type drive device of the loom described above as a premise, the crank hub of the mounting bracket is configured such that the fixing mechanism is located on the mounting surface side in the thickness direction of the mounting portion when the mounting surface of the mounting part abuts against the mounting surface of the bracket. Therefore, in this crank-type drive device, the position of the fixing mechanism in the crank hub becomes, in the axial direction, the side where the drive shaft is supported by the bearing compared to the mounting surface in the bracket. As a result, the distance in the axial direction from the portion of the drive shaft where the crank hub is fixed, in other words, from the portion of the drive shaft subjected to force from the driven component to the portion where the drive shaft is supported by the bearing, becomes shorter. That is, the execution length of the drive shaft becomes shorter. Therefore, compared to the case configured as in conventional devices, the drive shaft subjected to force from the driven component is less prone to deflection. Thus, in the crank-type drive device according to the present invention, it is difficult for the drive shaft to deflect, which is the cause of the aforementioned problems.

[0022] Furthermore, in the crank-type drive device of the loom of the present invention, by configuring the crank-type drive device such that the presence range of the fixing mechanism in the crank hub and the presence range of the bearing overlap in the axial direction of the drive shaft, the aforementioned execution length of the drive shaft is further shortened. As a result, this crank-type drive device is less prone to the aforementioned drive shaft deflection, and can prevent the aforementioned problems with higher accuracy. Attached Figure Description

[0023] Figure 1 This is a front view showing the pine needle pine device to which the present invention is applied.

[0024] Figure 2 This is an exploded perspective view showing the pine needle loosening device to which the present invention is applied.

[0025] Figure 3 This is a partial sectional view as a top view illustrating an embodiment of the present invention.

[0026] Figure 4 This is a front view illustrating an embodiment of the present invention.

[0027] Figure 5 This is a partial cross-sectional view taken from an off-center direction, illustrating another embodiment of the invention.

[0028] Symbol Explanation

[0029] 5—Warp beam, 7—Tension roller, 7a—Shaft section, 8—Support shaft, 10—Warp loosening device, 12—Warp loosening rod, 12A—Support hole, 12B—Support hole, 12C—Support hole, 14—Rod, 16—Arm, 18—Shaft assembly, 20—Crank-type drive device (drive device), 22—Crank hub, 22a—Shaft section, 22a1—Opening fastening mechanism (fixing mechanism), 22a2—Groove, 22a4—Opening fastening bolt, 22a5—Protrusion, 22b—Mounting part, 22c—Through hole, 22d—Mounting surface, 22e—Guide surface, 22f—Through hole, 22h—Insertion hole, 24—Bracket, 24b—Through hole, 24e—Bedding Mounting surface, 24J—enlarged part, 25—eccentric shaft part, 25b—through hole, 25f—engaging surface, 26—connecting component, 28—bearing, 29—fixing bolt, 32—loom frame, 34—drive shaft, 36—bearing, 40—crank-type drive device (drive device), 42—crank hub, 42a—shaft part, 42a1—opening fastening mechanism (fixing mechanism), 42a2—groove, 42a4—opening fastening bolt, 42a5—protrusion, 42b—mounting part, 42c—through hole, 42d—mounting surface, 42e—guide surface, 42f—through hole, T—warp yarn, L1—axis of shaft part 22, L2—axis of eccentric shaft part 25. Detailed Implementation

[0030] The following is based on Figures 1-5 One embodiment of the crank-type drive device of the present invention (this embodiment) will be described. Furthermore, this embodiment is an example of applying the present invention to a warp loosening device of a loom, as shown in the figures.

[0031] like Figure 1 and Figure 2 As shown, in the loom, the warp yarn T fed from the warp beam 5 is wound onto the tension roller 7 and guided to the weft end. Moreover, the warp loosening device 10 includes a pair of warp loosening rods 12, 12 supporting the tension roller 7 at both ends, crank-type drive devices (hereinafter referred to as "drive devices") 20, 20 corresponding to each warp loosening rod 12 and used for oscillating drive of the corresponding warp loosening rod 12, rods 14, 14 for connecting each warp loosening rod 12 and its corresponding drive device 20, and arms 16, 16.

[0032] Each warp release bar 12 is supported in a rotatable manner relative to the loom frame 32 via a support shaft 8 that fits into a support hole 12A formed at one end of the warp release bar 12. Furthermore, the tension roller 7 is supported by two warp release bars 12, 12, with its two end shaft portions 7a fitting into support holes 12B formed in the middle portion of each warp release bar 12. Therefore, the tension roller 7 is supported in a state where it can freely oscillate relative to the loom frame 32 about the axis of the support shaft 8 via each warp release bar 12.

[0033] Furthermore, a support hole 12C is formed at the other end of each loosening rod 12, and a shaft member 18 is fitted into the support hole 12C. Each loosening rod 12 is connected to an arm 16 via the shaft member 18. The arm 16 is connected to the drive device 20 via a rod 14. That is, each loosening rod 12 is connected to its corresponding drive device 20 via the shaft member 18, the arm 16, and the rod 14.

[0034] like Figure 3 and Figure 4 As shown, each drive unit 20 includes: a crank hub 22, which is non-rotatably mounted on the drive shaft 34; a bracket 24, which is non-rotatably mounted on the crank hub 22; an eccentric shaft portion 25, which is supported by the bracket 24; and a connecting member 26, which is rotatably supported by the bracket 24 via the eccentric shaft portion 25 and the bearing 28, and is connected to the corresponding rod 14.

[0035] Furthermore, the drive shaft 34 is rotatably supported on the loom frame 32 via bearings, with one end protruding outward from the loom frame 32 in the width direction (weave width direction) of the loom. The drive shaft 34 is also connected to the main shaft (not shown) of the loom via a drive transmission mechanism and is driven to rotate synchronously with the main shaft.

[0036] Furthermore, the crank hub 22 is configured to include: a shaft-shaped shaft portion 22a having a through hole 22c into which the drive shaft 34 is fitted; and a plate-shaped mounting portion 22b for mounting the bracket 24. The through hole 22c of the shaft portion 22a is centered on the axis L1 of the shaft portion 22. A fixing mechanism is provided in the shaft portion 22a to fix the crank hub 22 relative to the drive shaft 34 fitted into the through hole 22c. In this embodiment, the fixing mechanism is an opening fastening mechanism 22a1 including a groove communicating with the through hole 22c.

[0037] Furthermore, in the crank hub 22, the mounting portion 22b is plate-shaped as described above, and is integrally formed with the shaft portion 22a at one end in the axial direction, such that its thickness direction is aligned with the axial direction. Additionally, a through hole 22f is formed in the mounting portion 22b, communicating with the through hole 22c of the shaft portion 22a. This through hole 22f allows the drive shaft 34, which is inserted into the through hole 22c, to pass through. Furthermore, the mounting portion 22b has three through holes 22h for inserting fixing bolts 29, which are used to mount the bracket 24 to the crank hub 22.

[0038] Furthermore, regarding the bracket 24 and the eccentric shaft portion 25, in this embodiment, the bracket 24 and the eccentric shaft portion 25 are formed as a single unit. Specifically, the bracket 24 is formed in a generally plate-like shape for mounting to the plate-like mounting portion 22b in the aforementioned crank hub 22. Moreover, the eccentric shaft portion 25 is formed as a single unit with the bracket 24, protruding from one end face of the bracket 24 in the plate thickness direction. Thus, in this embodiment, the bracket 24 and the eccentric shaft portion 25 are formed as a single unit, whereby the eccentric shaft portion 25 (eccentric shaft) is supported by the bracket 24.

[0039] Furthermore, a through hole 25b for inserting the drive shaft 34 is formed in the eccentric shaft portion 25 such that its center coincides with the axis L2 of the eccentric shaft portion 25. Additionally, a through hole 24b is also formed in the bracket 24, communicating with the through hole 25b of the eccentric shaft portion 25. This through hole 24b is formed such that its inner diameter is larger than the inner diameter of the through hole 25b.

[0040] Furthermore, regarding the crank hub 22, bracket 24, and eccentric shaft portion 25 configured as described above, the front end of the portion of the crank hub 22 protruding from the loom frame 32 in the drive shaft 34, as described above, is non-rotatably mounted to the drive shaft 34 in a state where its front end portion is fitted into the through hole 22c. Moreover, the crank hub 22 is mounted relative to the drive shaft 34 using the aforementioned opening fastening mechanism 22a1. Therefore, the crank hub 22 can be mounted with its phase freely changing relative to the drive shaft 34.

[0041] Furthermore, the bracket 24 and the eccentric shaft portion 25 are arranged on the loom frame 32 side relative to the crank hub 22, with the eccentric shaft portion 25 positioned relative to the bracket 24 on the loom frame 32 side, and the drive shaft 34 inserted into the through holes 25b and 24b. Therefore, the end face of the bracket 24 opposite to the protruding side of the eccentric shaft portion 25 (the other end face) in its thickness direction faces the crank hub 22. Moreover, the bracket 24 is assembled to the crank hub 22 with its other end face abutting against the mounting portion 22b of the crank hub. Therefore, the aforementioned other end face of the bracket 24 becomes the mounting surface 24e of the crank hub 22.

[0042] Furthermore, the bracket 24 is assembled relative to the crank hub 22 using fixing bolts 29. More specifically, the bracket 24 has internal threaded holes (not shown) for threaded mounting of the fixing bolts 29 at positions corresponding to the three insertion holes 22h of the crank hub 22, with openings in the mounting surface 24e. With the bracket 24 in contact with the mounting portion 22b of the crank hub 22, the fixing bolts 29, which pass through the front end of the drive shaft 34 and threaded into the corresponding internal threaded holes of the crank hub 22, are thus assembled with the bracket 24 onto the crank hub 22.

[0043] Furthermore, the eccentric shaft portion 25, which is integrally formed with the bracket 24 assembled on the crank hub 22, is connected to the rod 14 on the tension roller 7 side, which is the drive component, via a connecting member 26. This connecting member 26 is a component with an annular portion, which is fitted into the eccentric shaft portion 25 via a bearing 28. Therefore, the connecting member 26 is rotatably supported by the bracket 24 via the eccentric shaft portion 25. Moreover, when the bearing 28 is fitted into the eccentric shaft portion 25, one end face of its axial direction abuts against the bracket 24.

[0044] Furthermore, in the drive device 20, which is a crank-type drive device, the drive device 20 needs to be configured such that the axis L2 of the eccentric shaft portion 25, which is connected to the rod 14 as described above, is eccentric relative to the axis L1 of the drive shaft 34. On the other hand, the drive shaft 34 is inserted into the through hole 25b of the eccentric shaft portion 25 as described above. Therefore, the through hole 25b of the eccentric shaft portion 25 is formed such that its inner diameter relative to the shaft diameter of the drive shaft 34 can achieve the desired eccentric state of the eccentric shaft portion 25 relative to the drive shaft 34.

[0045] Furthermore, the drive device 20 of this embodiment is configured to adjust the assembly position of the bracket 24 relative to the crank hub 22, so as to adjust the eccentricity of the axis L2 of the eccentric shaft portion 25 relative to the axis L1 of the drive shaft 34. More specifically, each insertion hole 22h of the crank hub 22 is formed as an elongated hole, as described above, in the direction (eccentric direction) connecting the axis L1 of the drive shaft 34 and the axis L2 of the eccentric shaft portion 25 when viewed along the axial direction of the drive shaft 34. Therefore, the assembly position of the bracket 24 with the fixing bolt 29 relative to the crank hub 22 can be adjusted within the range of its elongated hole, i.e., the insertion hole 22h.

[0046] In the drive unit 20 described above, as described above, the crank hub 22 of the drive shaft 34 is mounted on the drive shaft 34 at the front end side relative to the bracket 24, with the shaft portion 22a having the opening fastening mechanism 22a1 positioned relative to the mounting portion 22b on the loom frame 32 side. Thus, the bracket 24 is mounted on the crank hub 22 in a state where the mounting surface 24e abuts against the end face of the protruding side of the shaft portion 22a of the mounting portion 22b in the crank hub 22. Therefore, the end face of the mounting portion 22b in the state where the bracket 24 abuts becomes the mounting surface 22d of the crank hub 22.

[0047] Thus, in the drive unit 20, the crank hub 22 is configured such that the mounting surface 22d of the mounting bracket 24 is the end face of the protruding side of the shaft portion 22a in the mounting portion 22b. Furthermore, the crank hub 22 is mounted to the drive shaft 34 with its mounting surface 22d facing the loom frame 32 side, so that the bracket 24, which is positioned relative to the mounting portion 22b on the loom frame 32 side, is mounted to the crank hub 22 in contact with the mounting surface 22d. Moreover, as a result of the crank hub 22 being mounted to the drive shaft 34 and the bracket 24 being mounted to the crank hub 22, the opening fastening mechanism 22a1, as a fixing mechanism, is positioned relative to the mounting surface 24e of the bracket on the loom frame 32 side.

[0048] Furthermore, in this embodiment, the dimension of the shaft portion 22a of the crank hub 22 in the axial direction (=the axial direction of the drive shaft 34) is larger than the dimension in the thickness direction of the bracket 24. Therefore, when the bracket 24 is mounted on the crank hub 22 as described above (mounted state), the position of the end face of the other end of the shaft portion 22a is within the range of the eccentric shaft portion 25 located on the loom frame 32 side of the bracket 24 in the aforementioned axial direction. That is, in this structure, the range of the shaft portion 22a and the range of the eccentric shaft portion 25 overlap in the aforementioned axial direction. Moreover, since the bearing 28 is fitted into the eccentric shaft portion 25 as described above, the range of the bearing 28 overlaps with the range of the shaft portion 22a in the aforementioned axial direction. Therefore, the inner diameter of the through hole 25b of the eccentric shaft portion 25 becomes a diameter larger than the outer diameter of the shaft portion 22a.

[0049] Furthermore, the open-end fastening mechanism 22a1 provided on the shaft portion 22a includes, as described above, a groove 22a2, and a protrusion 22a5 protruding from the outer peripheral surface of the shaft portion 22a at a position continuous with the groove 22a2, and an open-end fastening bolt 22a4 threaded into the protrusion 22a5. Moreover, the groove 22a2 is formed throughout the axial direction of the shaft portion 22a. That is, the open-end fastening mechanism 22a1, as a fixing mechanism, exists throughout the area of ​​the shaft portion 22a in the aforementioned axial direction. Therefore, in the structure of this embodiment, the areas of the open-end fastening mechanism 22a1 (fixing mechanism) and the bearing 28 overlap in the axial direction of the drive shaft 34.

[0050] Furthermore, in this open-end fastening mechanism 22a1, the protrusion 22a5 of the shaft portion 22a is continuously formed from one end of the shaft portion 22a in the aforementioned axial direction, and is formed within the through hole 24b of the bracket 24 in the aforementioned installed state. Therefore, in the aforementioned installed state, the protrusion 22a5 is located within the through hole 24b of the bracket 24. Also, the open-end fastening bolt 22a4, which is threaded into the protrusion 22a5, is located within the through hole 24b of the bracket 24 in the aforementioned installed state.

[0051] Incidentally, in this embodiment, the threaded installation direction of the opening fastening bolt 22a4 relative to the protrusion 22a5 is the same as that of a typical opening fastening mechanism, and is orthogonal to the aforementioned axial direction. Furthermore, in the aforementioned installation state, the direction of the groove 22a2 when viewed along the aforementioned axial direction is consistent with the aforementioned eccentric direction. Therefore, the threaded installation direction of the opening fastening bolt 22a4 is orthogonal to the aforementioned eccentric direction when viewed along the aforementioned axial direction.

[0052] Furthermore, in order to allow operation of the opening fastening bolt 22a4 of the crank hub 22 located on the loom frame 32 side from the front end side of the drive shaft 34 in the aforementioned installation state, the crank hub 22 mounting portion 22b is as follows: Figure 4 As shown, it is formed such that the opening fastening bolt 22a4 is exposed when viewed along the aforementioned axial direction. Specifically, when viewed along the aforementioned axial direction, a portion of the mounting portion 22b is formed to match the shape of the portion in the protrusion 22a5 that inserts the opening fastening bolt 22a4 on one side.

[0053] Furthermore, in the bracket 24, to accommodate the open-end fastening mechanism 22a1 (protrusion 22a5, open-end fastening bolt 22a4) provided on the shaft portion 22a as described above, the through hole 24b is formed with an enlarged portion 24J, which is an enlarged portion facing the head of the open-end fastening bolt 22a4 in the above-described installation state, and its periphery is enlarged in a direction orthogonal to the above-described eccentric direction (the threaded installation direction of the open-end fastening bolt 22a4). Moreover, this enlarged portion 24J is formed such that the size of the open-end fastening bolt 22a4 can be manipulated with a tool in the above-described installation state.

[0054] Furthermore, in this embodiment, in order to guide the movement of the bracket 24 and the eccentric shaft portion 25 relative to the crank hub 22 in the eccentric direction, a pair of guide surfaces 22e, 22e are formed on the outer peripheral surface of the shaft portion 22a of the crank hub 22, and a pair of engaging surfaces 25f, 25f are formed on the eccentric shaft portion 25 to engage with the pair of guide surfaces 22e, 22e.

[0055] More specifically, the crank hub 22's shaft portion 22a has two parallel planes 22e, 22e at its other end, formed by cutting a portion of its outer circumferential surface. When viewed along the aforementioned axial direction, the direction of each plane 22e coincides with the direction of the groove 22a2 in the open fastening mechanism 22a1 (i.e., the aforementioned eccentric direction). Furthermore, this plane 22e functions as a guide surface in the shaft portion 22a.

[0056] Furthermore, the eccentric shaft portion 25 is formed such that the portion of its inner circumferential surface of the through hole 25b that faces each guide surface 22e of the shaft portion 22a in the above-described installation state is a plane 25f parallel to each guide surface 22e in the above-described installation state. Moreover, the through hole 25b is formed such that the interval between its two planes 25f, 25f is approximately the same as the interval between the two guide surfaces 22e, 22e in the shaft portion 22a, and the portion with the plane 25f protrudes inwards more than the other portions. Thus, in the above-described installation state, each guide surface 22e of the shaft portion 22a engages with the opposing plane 25f in the through hole 25b, and this plane 25f functions as the engaging surface in the eccentric shaft portion 25. Furthermore, when the fixing bolts 29 are loosened, each engaging surface 25f of the eccentric shaft portion engages with and slides into contact with the corresponding guide surface 22e of the shaft portion 22a, thereby guiding the movement of the bracket 24 in the above-described eccentric direction.

[0057] As described above, in the crank-type drive device 20, the crank hub 22 is configured such that the sheath fastening mechanism 22a1 is located on the mounting surface 22d side in the plate thickness direction of the mounting portion 22b1. Therefore, the crank-type drive device 20 is configured such that, in the above-described mounting state, the position of the sheath fastening mechanism 22a1 in the above-described axial direction is the side of the drive shaft 34 supported by the bearing 36 (loom frame 32 side) relative to the mounting surface 24e of the bracket 24.

[0058] As a result, the distance in the axial direction from the portion of the drive shaft 34 that is fixed to the crank hub 22 to the portion of the drive shaft 34 that is supported by the bearing 36, i.e., the execution length of the drive shaft 34, is shorter than in the existing structure (conventional structure) where the mounting surface 24e of the bracket 24 becomes the front end side of the drive shaft 34, compared to the position of the open fastening mechanism in the above-described installed state. Therefore, in this crank-type drive device 20, compared to the above-described conventional structure, the drive shaft 34, subjected to the force from the tension roller 7, which is the driven component, is less prone to deflection.

[0059] Furthermore, as described above, the crank-type drive device 20 is configured such that the area of ​​the open fastening mechanism 22a1 in the crank hub 22 overlaps with the area of ​​the bearing 28 fitted into the eccentric shaft portion 25 in the aforementioned axial direction. As a result, the aforementioned execution length of the drive shaft 34 of the crank-type drive device 20 is shorter, making it more difficult for the drive shaft 34 to flex.

[0060] The above describes one embodiment of the crank-type drive device for the loom of the present invention, but the crank-type drive device for the loom of the present invention is not limited to the above embodiment, and can also be implemented in the following modified examples.

[0061] (1) Regarding the open-end fastening mechanism 22a1, in the crank-type drive device 20 of the above embodiment, an open-end fastening mechanism 22a1 provided on the shaft portion 22a of the crank hub 22 is used as a fixing mechanism, and the thread mounting direction of the open-end fastening bolt 22a4 relative to the protrusion 22a5 of the shaft portion 22a is orthogonal to both the axial direction and the eccentric direction. However, even when an open-end fastening mechanism is used as a fixing mechanism, the thread mounting direction is not limited to the above-described direction; for example, it can be as follows: Figure 5 The setting shown is such that, when viewed along the aforementioned eccentric direction, the open-end fastening bolt 22a4, which is threadedly inserted in a direction inclined relative to the direction orthogonal to the aforementioned axial direction, is inclined such that the head side is located at the front end of the drive shaft 34 compared to the shaft side. Furthermore, with this threaded mounting direction set, the operation of the open-end fastening bolt can be made easier.

[0062] (2) In the crank-type drive device 20 of the above embodiment, an open fastening mechanism 22a1 is used as a fixing mechanism for fixing the crank hub 22 to the drive shaft 34. However, in the crank-type drive device of the present invention, the fixing mechanism is not limited to the open fastening mechanism described above. For example, it may be an annular friction fastener such as "POSI LOCK" (registered trademark) manufactured by Miki Poly Corporation or "expansion sleeve" (registered trademark) manufactured by Lingfeida Corporation. Moreover, when such a friction fastener is used, the friction fastener is clamped between the inner circumferential surface of the through hole of the crank hub and the drive shaft, and functions as a fixing mechanism.

[0063] Furthermore, when using the aforementioned annular friction fastener as the fixing mechanism, the through hole of the bracket can be formed as a hole capable of accommodating the inner diameter of the fixing mechanism, and can be formed without the aforementioned enlarged portion. Moreover, even when using an open fastening mechanism as the fixing mechanism as in the above embodiment, if the through hole of the bracket 24 is formed as a hole capable of fully accommodating the inner diameter of the fixing mechanism, the through hole can also be formed without the aforementioned enlarged portion. Thus, the bracket of the crank-type drive device of the present invention is not limited to having the enlarged portion of the above embodiment in the through hole.

[0064] (3) In the crank-type drive device 20 of the above embodiment, the areas where the opening fastening mechanism 22a1, which serves as the fixing mechanism, and the bearing 28 exist overlap in the axial direction. However, the crank-type drive device of the present invention is not limited to this configuration, and it may also be configured such that the areas where the fixing mechanism and the bearing 28 exist do not overlap in the axial direction. Specifically, for example, by making the dimension in the axial direction of the shaft portion of the crank hub where the fixing mechanism is provided smaller than the dimension in the plate thickness direction of the bracket 24, the area where the shaft portion exists in the axial direction becomes the front end side of the drive shaft 34 relative to the eccentric shaft portion and the bearing 28 fitted into the eccentric shaft portion.

[0065] (4) The crank-type drive device 20 of the above embodiment is configured such that, when viewed along the axial direction, each insertion hole 22h of the crank hub 22 is formed as an elongated hole in the eccentric direction. By adjusting the assembly of the bracket 24 with fixing bolts 29 relative to the crank hub 22 within the range of the elongated hole, the eccentricity of the axis L2 of the eccentric shaft portion 25 relative to the axis L1 of the drive shaft 34 can be adjusted. However, the crank-type drive device of the present invention may also be configured such that the eccentricity is a constant amount (fixed amount) (the assembly position of the bracket relative to the crank hub is fixed). Specifically, it may also be configured such that, when viewed along the axial direction, each insertion hole of the crank hub 22 is formed as a circular hole.

[0066] (5) Furthermore, the above embodiment is an example of applying the crank-type drive device 20 of the loom of the present invention to the warp loosening device of the loom. However, the device on the loom to which the crank-type drive device of the present invention is applied is not limited to the warp loosening device, and may also be, for example, the shedding device disclosed in Patent Document 2. Moreover, the device used in this application may also be the raising action mechanism in the raising loom disclosed in Patent Document 3.

[0067] Furthermore, the present invention is not limited to any of the embodiments described above, and can be appropriately modified without departing from its spirit.

Claims

1. A crank-type drive device for a loom, comprising a crank hub non-rotatably mounted to a drive shaft, a bracket non-rotatably mounted to the crank hub, an eccentric shaft supported by the bracket and having a through hole through which the drive shaft is inserted, the through hole being a hole with an inner diameter capable of achieving an eccentric state relative to the drive shaft, and a connecting member rotatably supported by the bracket via the eccentric shaft and a bearing and connected to a drive component of the loom, the bracket having a mounting surface mounted on the crank hub, the mounting surface being orthogonal to the axis of the drive shaft and being a front end side of the drive shaft, the crank hub having: a mounting portion, which is a plate-shaped mounting portion for mounting the mounting surface of the bracket and having a mounting surface abutting against the mounting surface; and a fixing mechanism for fixing the crank hub to the drive shaft and fitting into the drive shaft, characterized in that... The crank hub is configured such that the fixing mechanism is located on the mounting surface side in the plate thickness direction of the mounting part.

2. The crank-type drive device for a loom according to claim 1, characterized in that, The range of the aforementioned fixing mechanism in the crank hub and the range of the aforementioned bearing overlap in the axial direction of the aforementioned drive shaft.

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