JP5539697B2 - Shaft coupling - Google Patents

Description

  The present invention relates to a shaft joint capable of absorbing a deviation in each direction between a first shaft and a second shaft to be coupled.

  2. Description of the Related Art Conventionally, a plate spring type coupling that utilizes the deflection of a leaf spring has been provided as a flexible shaft joint that couples a first shaft and a second shaft (see, for example, Patent Document 1). As shown in FIG. 8, an intermediate member (spacer) 3 is provided between a first shaft coupling member 1 to which a motor shaft is mounted and a second shaft coupling member 2 to which a detector shaft is mounted, for example. The first plate spring 4 and the second plate spring 5 are arranged with being sandwiched, and these are connected by using a plurality of bolts 6, nuts 7, washers 8, and the like. With this configuration, it is possible to transmit torque while absorbing the radial misalignment, axial displacement, and deflection angle between the shafts by the first plate spring 4 and the second plate spring 5 being bent and deformed. It has become.

JP 2000-320666 A

  However, in the above-described flexible shaft joint using the deflection of the leaf springs 4 and 5, since torque transmission is the main focus, the allowable values of radial misalignment, axial displacement, and deflection angle between the shafts are compared. It was very small. By the way, in the catalog information, for example, the allowable value of radial misalignment between shafts is 0.3 mm (recommended within 0.1 mm), the allowable value of axial displacement is 1 mm, and the allowable value of declination is angle 1. 5 °, etc.

  For this reason, the conventional shaft joint requires precise work for the initial setting of the shafts in practical use. Or, when the amount of misalignment between the shafts increases due to wear or the like associated with long-term use, if the use situation exceeds the allowable range, fatigue damage occurs relatively easily. For example, the leaf springs 4, 5 There is a problem that the end portion (connection portion by the bolt) of the wire is easily broken.

  The present invention has been made in view of the above circumstances, and the object thereof is to sufficiently increase the allowable range regarding the radial misalignment, the axial displacement, and the deflection angle between the shafts, and suppress the occurrence of fatigue failure. Is to provide a shaft joint that can.

In order to achieve the above object, a shaft joint of the present invention includes a first body to which a first shaft is fixed, and a second body that is disposed opposite to the first body and to which a second shaft is fixed. And connecting the first body and the second body, and four connecting members provided at intervals of 90 degrees or three at intervals of 120 degrees, and each connecting member is makes the elastic deformable elongated strip of a metal plate material to bending formation, a first arm portion extending in the outer peripheral direction base end portion is fixed to the first body, the tip of the first arm A quadrangular joint extending from the tip of the joint to the second body side and extending in the axial direction, and a tip extending from the tip of the joint to the inner peripheral direction so as to be parallel to the first arm. It is configured to a U-shape integrally having a second arm portion which is fixed to the second body The misalignment between the shafts in the radial direction is absorbed by a deflection deformation such that the two arms of the connecting member are displaced in parallel, a deflection deformation in the torsional direction, or a deflection deformation that combines them, and the two shafts. The axial displacement of the connecting member is absorbed by bending deformation so that the distance between the tip portions of the two arm portions of the connecting member is narrowed or widened. It is characterized in that it is absorbed by a deflection deformation that is a combination of a deflection deformation shifted in the parallel direction between the tips of the two arm portions of the member, a deflection deformation in the torsional direction, a deflection deformation in the expansion / contraction direction, and the like. invention).

  According to the above configuration, the first body and the second body are connected by the plurality of connecting members, but can be elastically deformed from the metal plate material to the gate shape (U-shape). The connecting member is easily deformed by receiving a force in each direction. That is, misalignment in the radial direction between the shafts can be absorbed by bending deformation in which the two arm portions of the connecting member are displaced in parallel, bending deformation in the torsional direction, or bending deformation that combines them. The axial displacement of the two shafts can be absorbed by bending deformation so that the distance between the tip portions of the two arm portions of the connecting member is narrowed or widened. Regarding the occurrence of the declination, as described above, the deflection deformation that combines the two arm portions of the connecting member that are displaced in the parallel direction, the deflection deformation in the twist direction, the deflection deformation in the expansion / contraction direction, etc. Can be absorbed.

  At this time, it is possible to sufficiently increase the tolerance for displacement in any direction as compared with the conventional one using a flexible plate made of a leaf spring. In the present invention, torque transmission between the first shaft and the second shaft is performed while each connecting member is flexibly deformed in the torsional direction. In this case, since the rigidity of the connecting member is relatively low, large torque transmission cannot be expected, but it is suitable when the required torque is small.

  According to the shaft joint of the present invention, in the shaft joint capable of absorbing the displacement in each direction between the first shaft and the second shaft to be coupled, the first body, the second body, Is configured to be connected by a plurality of connecting members made of elastically deformable gate-shaped metal plates, so that the allowable range regarding the radial misalignment, axial displacement, and deflection angle between the shafts is sufficiently increased. This produces an excellent effect that the occurrence of fatigue failure can be suppressed.

1 is a perspective view of a shaft joint according to a first embodiment of the present invention. Front view of shaft joint (a), vertical right side view along line BB (b) and vertical left side view along line CC (c) Longitudinal front view (a) and right side view (b) of the first body Front view (a) and right side view (b) of one connecting member The figure which exaggerates and shows the mode of a bending deformation of a connecting member with respect to the shift | offset | difference of each direction (3 types) of shafts. The 2nd Example of this invention is shown, The top view (development figure) (a) before bending formation of a connection member, and the perspective view (b) after bending formation FIG. 3 shows a third embodiment of the present invention and is equivalent to FIG. An exploded perspective view of a flexible shaft joint showing a conventional example.

(1) First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 show the overall configuration of the shaft joint 11 according to the present embodiment. The shaft joint 11 of the present embodiment is not shown, but for example, a motor shaft as a first shaft and an input shaft of a measuring instrument as a second shaft for measuring the angle of the motor shaft. It is used for the purpose of connecting between. In the following description, a state in which the first shaft and the second shaft extend in the left-right direction, that is, the state shown in FIG. 2A is a front view, and for convenience, the first and second bodies (described later) are used. ) Is on the side with the keyway.

  The shaft joint 11 is located on the left side in the figure and has a first body 12 to which a first shaft (motor shaft) is fixed. The shaft joint 11 is located on the right side in the figure and is disposed opposite to the first body 12 and is disposed on the second axis. The second body 13 to which (the input shaft of the measuring instrument) is fixed, and a plurality of, in this case, four connecting members 14 that connect the first body 12 and the second body 13 are configured. The At this time, these four connecting members 14 are provided at equal intervals (at an angle of 90 °), respectively in the vertical and front-rear directions.

  Of these, the first body 12 and the second body 13 have a symmetrical (substantially equivalent) configuration, and therefore the first body 12 will be described below. FIG. 3 shows the first body 12 as a representative. The first body 12 is made of a metal, for example, stainless steel (SUS304) in a substantially cylindrical shape, and the inner side (second body 13). On the surface facing the side), there is a convex portion 12a which is located in the central portion and is circularly convex.

  In addition, an insertion hole 15 into which the motor shaft (not shown) is inserted is formed at the center of the first body 12 so as to penetrate through the protrusion 12a. A key groove 15a is formed at the upper part of the inner peripheral surface of 15 and extends in the entire axial direction. Incidentally, an example of the dimensions of each part of the first body 12 will be described. As shown in FIG. 3A, the diameter (outer diameter) dimension a is 40 mm, and the axial length dimension b including the convex part 12a is 24.5 mm (of which the protruding dimension of the convex part 12a is 5 mm), the diameter dimension c of the convex part 12a is 23 mm, and the diameter dimension d of the insertion hole 15 is 15 mm.

  Further, the first body 12 is formed with two screw holes 16, 16 extending radially from the outer peripheral surface toward the center and opening in the insertion hole 15, that is, extending through the inner and outer periphery. Has been. As shown in FIG. 3, one of the screw holes 16 extends vertically so as to open in the key groove 15a, and the other screw hole 16 is horizontally placed at a position 90 degrees away from the screw hole 16. It is extended. The first shaft can be fixed by screwing a set screw 17 (see FIG. 2A) into the screw holes 16. Although not shown, when there is a keyway on the first shaft, it is a matter of course that the first shaft can be fixed using a key.

Then, on the surface facing the inner side of the first body 12 (on the convex portion 12a side), a 4 is provided for attaching a connecting member 14 to be described later, located on the outer peripheral portion (the outer peripheral portion of the convex portion 12a ). A plurality of connecting screw holes 18 are formed. As shown in FIG. 3B, the four connecting screw holes 18 are formed at equal intervals (90 ° intervals) at 45 ° oblique positions with respect to the vertical and horizontal directions when viewed in the axial direction. Yes. Although not described in detail, the second body 13 has a convex portion 13a on the surface facing the inner side (first body 12 side) as shown in part in FIG. 1 and FIG. In addition, there are formed an insertion hole 15 having a key groove 15a into which the second shaft is inserted, two screw holes 16, 16, and four connecting screw holes 18.

  Now, the connecting member 14 will be described. FIG. 4 shows one connecting member 14, which is an elongated elastically deformable metal plate material, for example, a thin plate of stainless steel (SUS304) having a thickness of 0.5 mm, which is a portal type (copper). It is formed by forming a bent shape. Specifically, as shown in FIGS. 1, 2, and 4, the connecting member 14 includes a first arm portion 19 that is fixed to the inner surface of the first body 12 and extends in the outer circumferential direction, and the first arm portion 19. A connecting portion 20 that is bent from the tip of one arm portion 19 toward the second body 13 and extending in the axial direction; and a tip that extends from the tip of the connecting portion 20 in the inner peripheral direction is the second body. And a second arm portion 21 fixed to the inner surface of 13.

  At this time, as shown in FIG. 4B, both end portions of the connecting member 14, that is, the proximal end portion of the first arm portion 19 and the distal end portion of the second arm portion 21, The attachment parts 22 and 22 for fixing to the two bodies 12 and 13 are integrally provided. These mounting portions 22 and 22 have arcuate (semicircular) cutouts corresponding to the outer peripheries of the convex portions 12a and 13a. Each mounting portion 22 is formed with two bolt insertion holes 22 a corresponding to the connecting screw holes 18. These bolt insertion holes 22 a are provided so as to wrap in two adjacent connecting screw holes 18 among the connecting screw holes 18.

  In addition, the connection member 14 has comprised the strip | belt shape (strip shape) of an equal width dimension about the site | part except the attaching part 22 of the both ends. Further, as shown in FIG. 4A and the like, a bent portion between the first arm portion 19 and the connecting portion 20 and a bent portion between the connecting portion 20 and the second arm portion 21. Is in a state having a small curvature (R). Incidentally, as an example of the dimensions of each part of the connecting member 14, as shown in FIG. 4, the width dimension e of the belt-like part excluding the attachment part 22 at both ends is 20 mm, the first arm part 19 and the second arm part 19 The length dimension f of the arm portion 21 in the diameter direction is 54 mm, and the length dimension g of the connecting portion 20 is 30 mm.

  As shown in FIGS. 1 and 2, the four connecting members 14 configured as described above are arranged vertically between the first body 12 and the second body 13 facing left and right (vertical direction). ) And front and rear (horizontal direction), respectively, are fixed as follows, and the first body 12 and the second body 13 are connected.

  That is, the two connecting members 14 and 14 positioned above and below the first body 12 are arranged so that the ends of the mounting portion 22 of the first arm portion 19 abut each other vertically. It arrange | positions in the outer peripheral part of the convex part 12a of a surface (right surface in a figure). Further, the two connecting members 14, 14 positioned in the front-rear direction of the connecting members 14, 14 positioned in the up-down direction are arranged such that the end portions of the mounting portion 22 of the first arm portion 19 are abutted in the front-rear direction. It arrange | positions so that it may overlap with the inner side (right side) of the attaching part 22 of the 1st arm part 19. FIG.

  At this time, the bolt insertion holes 22 a formed in the respective attachment portions 22 are positioned so as to wrap around the four connecting screw holes 18 formed in the first body 12. Then, by screwing the four bolts 23 from the inside into the connecting screw holes 18 through the bolt insertion holes 22a, the first arm portions 19 (mounting portions 22) of the four connecting members 14 are the first ones. It is fixed to the body 12.

  Similarly, the two connecting members 14, 14 positioned in the front-rear direction with respect to the second body 13 are arranged so that the end portions of the mounting portion 22 of the second arm portion 21 abut each other in the front-rear direction. Is disposed on the outer peripheral portion of the convex portion 13a on the surface (left surface in the figure). Further, the two connecting members 14 and 14 positioned above and below are arranged so that the end portions of the mounting portion 22 of the second arm portion 21 are vertically butted against each other, while the connecting members 14 and 14 positioned in the front and rear are disposed. It arrange | positions so that it may overlap with the inner side (left side) of the attaching part 22 of the 2nd arm part 21. FIG.

  At this time, the bolt insertion holes 22a of the respective attachment portions 22 are also wrapped in the connection screw holes 18, and four bolts 23 are screwed into the connection screw holes 18 from the inside through the bolt insertion holes 22a. The second arm portion 21 (attachment portion 22) of the connecting member 14 is fixed to the second body 13.

  Next, the operation of the shaft joint 11 configured as described above will be described with reference to FIG. As described above, for example, the motor shaft as the first shaft is fixed to the first body 12 in a state of being inserted into the insertion hole 15, and the second body 13 has the second shaft as the second shaft. The input shaft of the angle measuring instrument is fixed in a state where it is inserted into the insertion hole 15. In this case, as a method of fixing the shaft, a method using a key or a method using a set screw 17 can be employed.

  Here, since it is difficult to dispose the first axis and the second axis so as to be completely aligned with each other without being displaced in each direction, the shaft joint 11 has a certain degree in each direction between the axes. A function of coupling (connecting) while allowing deviation (displacement) is required. In the shaft joint 11 of the present embodiment, the displacement in each direction between the shafts can be absorbed (escaped) as follows using the flexural deformation of the connecting member 14.

  That is, FIG. 5 shows exaggeratedly (exaggeratedly) the state of the bending deformation of the connecting member 14 with respect to the displacement of the shafts in each direction. First, with respect to misalignment in the radial direction between the shafts (the vertical direction is illustrated in FIG. 5A), the two connecting members 14 positioned in the vertical direction (vertical direction) are shown in FIG. 5A. As described above, the first arm portion 19 and the second arm portion 21 are bent and deformed so as to be displaced in parallel in the vertical direction. At the same time, as shown in FIG. 5B, the two connecting members 14 positioned in the front-rear direction (lateral direction) are gradually bent and deformed in the twisting direction. When the shaft rotates, the connecting member 14 bends and deforms as if the two states in FIGS. 5A and 5B are combined. Since the connecting member 14 has a thin plate shape that can be elastically deformed, the generated stress is small, and the misalignment between the axes can be easily absorbed.

  Next, with respect to the axial displacement between the shafts (displacement in the contact / separation direction along the axis), the interval between the tip portions of the first arm portion 19 and the second arm portion 21 of the connecting member 14 is reduced. Absorption can be achieved by bending deformation so as to spread. FIG. 5C illustrates a state in which the shafts are bent and deformed so that the distal ends of the first arm portion 19 and the second arm portion 21 of the connecting member 14 expand. Also in this case, the axial displacement between the shafts can be easily absorbed.

  Further, with respect to the occurrence of the deflection angle between the shafts, the connecting member 14 is bent and deformed as appropriately combined with the states shown in FIGS. 5 (a), (b), and (c). The occurrence of the deflection angle between the axes can be easily absorbed. As described above, according to the shaft joint 11 of this embodiment, by using the thin plate-like connecting member 14 that can be elastically deformed, in any direction compared to the conventional one using a flexible plate made of a leaf spring. However, it is possible to sufficiently increase the tolerance for the deviation. Of course, the initial setting between the shafts does not require precision work.

  In the shaft joint 11, torque transmission between the first shaft and the second shaft is performed while each connecting member 14 is flexibly deformed in the torsional direction as shown in FIG. 5B. become. In this case, since the rigidity of the connecting member 14 is relatively low, large torque transmission cannot be expected. Therefore, the shaft joint 11 is suitable for use when the required torque is small.

  As is apparent from the above description, according to the shaft joint 11 of the present embodiment, the first body 12 and the second body 13 are connected to each other by a plurality of joints made of a gate-shaped metal plate that can be elastically deformed. Since the members 14 are connected to each other, the shaft joint 11 is capable of absorbing the displacement in each direction between the first shaft and the second shaft to be coupled, and the shafts are misaligned in the radial direction. In addition, it is possible to sufficiently increase the permissible range regarding the axial displacement and the deflection angle, and it is possible to suppress the occurrence of fatigue failure.

  In particular, in the present embodiment, four connecting members 14 are provided at equal intervals (90 °) between the first body 12 and the second body 13, so It is also possible to obtain an advantage that the bending deformation of the connecting member 14 with respect to the deviation is performed in a stable state without deviation in the circumferential direction. Incidentally, in the fatigue test conducted by the present inventor for the shaft joint 11 of the present embodiment, a fatigue test of 10 million times under the condition that the amount of misalignment in the radial direction is 3 mm and the amount of axial displacement is 1.6 mm. Passed.

(2) Second and third embodiments and other embodiments FIG. 6 shows a second embodiment of the present invention. The difference from the first embodiment is the structure of the connecting member. is there. In the second embodiment, an integrated connecting member 31 is used in which two connecting members arranged so as to be linearly arranged in the diameter direction are integrally connected. That is, the integrated connecting member 31 is formed by integrating the end portions (attachment portions 22) of the first arm portion 19 that are abutted vertically (or front and rear) in the connecting member 14 in the first embodiment. The shape is connected to

  That is, FIG. 6A shows the shape of the stainless steel plate 32 before the integrated connecting member 31 is bent (in a state of being punched out by a press). A substantially ring-shaped central mounting portion 33 is provided at the central portion of the plate member 32 such that the two mounting portions 22 are integrated, and the first arm extends from the central mounting portion 33 in both the left and right directions in the drawing. The portion 19 is integrally continuous, and further extends in both the left and right directions, and the connecting portion 20 and the second arm portion 21 are integrally provided continuously through the fold s. An attachment portion 22 is provided at the end of the second arm portion 21. A circular hole corresponding to the convex portion 12a of the first body 12 is formed in the central mounting portion 33, and four bolt insertion holes 33a are formed around it.

  By bending such a plate member 32 at approximately 90 ° at four folds s, an integrated connecting member 31 having the form shown in FIG. 6B is obtained. As in the first embodiment, the first body 12 and the second body 13 are fixed to each other by bolting and connected to each other. According to the second embodiment, like the first embodiment, in the shaft joint, the allowable range regarding the radial misalignment, the axial displacement, and the deflection angle between the shafts is sufficiently large. And the effect of suppressing the occurrence of fatigue failure can be obtained. In addition to this, it is possible to reduce the number of parts of the connecting member and to improve the efficiency of assembly work.

  FIG. 7 shows a shaft joint 41 according to a third embodiment of the present invention. In this shaft joint 41, the first body 42 to which the first shaft is fixed and the second body 43 to which the second shaft is fixed are connected by an elastically deformable connecting member 44. However, here, the connection is made by three connection members 44 arranged at equal angle intervals (120 °). Even with the shaft joint 41 having such a configuration, it is possible to obtain substantially the same operations and effects as the shaft joint 11 of the first embodiment.

In the above embodiments, first, the material of the second body and the coupling member, the first, and the size of each part of the second body, the thickness of the coupling member, for such each unit of length is one example However, it is possible to design according to required performance (amount of deflection to be allowed) and the like.

  In addition, the present invention is not limited to the above-described embodiments, such as various types of modifications such as the types of axes (first axis and second axis) to be combined. The present invention can be implemented with appropriate modifications within a range that does not depart.

  In the drawings, 11 and 41 are shaft joints, 12 and 42 are first bodies, 13 and 43 are second bodies, 14 and 44 are connecting members, 19 is a first arm portion, 20 is a connecting portion, and 21 is a connecting portion. The second arm portion, 22 is an attachment portion, and 31 is an integral connecting member.

Claims (1)

A first body to which the first shaft is fixed;
A second body disposed opposite to the first body and having a second shaft fixed thereto;
The first body and the second body are connected to each other, and includes four connecting members provided at intervals of 90 degrees or three at intervals of 120 degrees,
Wherein each connecting member comprises a elastic deformable elongated strip of a metal plate material to bending formation, a first arm having a base end portion extending in secured to the outer circumferential direction in the first body, the first A quadrangular joint extending in the axial direction from the tip of the arm to the second body, and bent in the inner circumferential direction from the tip of the joint to be parallel to the first arm The tip is configured to have a U-shape integrally having a second arm portion with a tip extended to be fixed to the second body,
The misalignment between the shafts in the radial direction is absorbed by a deflection deformation such that the two arms of the connecting member are displaced in parallel, a deflection deformation in the torsional direction, or a deflection deformation that combines them, and the two shafts. The axial displacement of the connecting member is absorbed by bending deformation so that the distance between the tip portions of the two arm portions of the connecting member is narrowed or widened. A shaft joint characterized in that it is absorbed by a flexural deformation that is a combination of a flexural deformation that shifts in the parallel direction between the tips of the two arms of the member, a flexural deformation in the torsional direction, a flexural deformation in the expansion / contraction direction, and the like.

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