WO2020044437A1

WO2020044437A1 - Shaft coupling

Info

Publication number: WO2020044437A1
Application number: PCT/JP2018/031771
Authority: WO
Inventors: 剛一岩井
Original assignee: 鍋屋バイテック株式会社
Priority date: 2018-08-28
Filing date: 2018-08-28
Publication date: 2020-03-05
Also published as: JP7036466B2; JPWO2020044437A1

Abstract

This shaft coupling is provided with: two hubs each having a shaft hole into which a shaft is fitted; and a rotation transmitting section for transmitting rotation between both hubs. At least one of the two hubs has an expansion operation section which increases the diameter of the shaft hole by means of external operation, and which, after the external operation is stopped, permits, because of the elasticity of the at least one of the hubs, a reduction in the diameter of the shaft hole.

Description

Shaft coupling

The present invention relates to a shaft coupling.

Patent Documents 1 and 2 disclose a shaft coupling disposed between a drive shaft and a driven shaft. This type of shaft coupling has a drive hub connected to the drive shaft, a driven hub connected to the driven shaft, and a rotation transmission unit that transmits rotation between the two hubs.

The conventional connection between the drive hub and the drive shaft and the connection between the driven hub and the driven shaft are performed as follows.
In Patent Literature 1, the driving hub (the first shaft coupling member in Patent Literature 1) and the driven hub (the second shaft coupling member in Patent Literature 1) include a shaft hole that penetrates in the axial direction, and a shaft hole. And a slot formed radially in communication with the slot.

In the drive hub, a bolt hole is formed on one side of the slot, and a screw hole is formed on the other side. Then, by passing the slit from the side of the bolt through hole and tightening the fastening bolt into the screw hole, the groove width of the slit groove is reduced, and as a result, the shaft hole diameter is reduced, and the shaft hole is narrowed. The fitted drive shaft is securely fastened to the drive hub. The connection between the driven hub and the driven shaft is performed in the same manner.

In Patent Literature 2, the drive hub (the cylindrical portion in Patent Literature 2) includes a shaft hole (an insertion hole in Patent Literature 2) penetrating in the axial direction and a screw formed in the radial direction while communicating with the shaft hole. With holes. In the drive hub, a set screw is screwed into the screw hole, and abuts on the drive shaft fitted into the shaft hole, whereby the drive shaft fitted into the shaft hole moves with respect to the drive hub. It is firmly fastened. The connection between the driven hub and the driven shaft is performed in the same manner.

JP 2014-92168 A JP 2014-52016 A

The drive shaft and the driven shaft respectively fitted into the shaft hole of the drive hub and the driven hub, when the drive shaft, the driven shaft, and the shaft coupling are vibrated during use, the fastening bolt or the set screw is loosened, There is a possibility that the fastening of the hub to the drive shaft or the driven shaft is loosened.

An object of the present invention is to provide a shaft coupling that does not loosen the connection of the hub to the shaft even when vibration is applied.

A shaft coupling that solves the above problem includes two hubs each having a shaft hole into which a shaft is fitted, and a rotation transmission unit that transmits rotation between both hubs, and at least one of the two hubs. The hub has an expanding operation portion that expands the diameter of the shaft hole by an external operation, and allows the diameter of the shaft hole to be reduced by elasticity of at least one of the hubs after the external operation is released.

According to the above configuration, when the shaft is connected to the shaft hole of at least one hub, the diameter of the shaft hole is made to be larger than the diameter of the shaft by operating the expanding operation section externally, and in this state, the shaft is expanded. The shaft is fitted into the shaft hole in a state where the diameter is large. Thereafter, after releasing the expanding operation portion, the diameter of the shaft hole is allowed to be reduced by the elasticity of the at least one hub, and the shaft and the hub are connected.

Further, each of the two hubs may include the expanding operation section.
According to the above configuration, when connecting the shafts to the shaft holes of both hubs, each expanding operation portion is externally operated so that the diameter of the corresponding shaft hole is expanded to be larger than the diameter of the connecting shaft. In this state, a corresponding shaft is fitted into the shaft hole whose diameter has been increased. Thereafter, after releasing the expanding operation portion, the diameter of the shaft hole is permitted by the elasticity of each hub, and the shaft and the hub are connected.

Further, the expanding operation portion may be a split groove having a female screw extending in a radial direction of the at least one hub, and the external operation is to screw a male screw to the female screw of the split groove. The external operation may be released by releasing the external thread from the split groove.

According to the above configuration, the diameter of the shaft hole is expanded by screwing a male screw into the female screw of the split groove of the at least one hub. After the male screw is released from the split groove, the diameter of the shaft hole is reduced.

Further, the male screw may be a headed bolt, and the female screw may have a locking edge with which the head of the headed bolt is locked.
With the above configuration, the headed bolt screwed into the female screw of the split groove of the hub is locked to the locking edge, and when the headed bolt is further screwed, the diameter of the shaft hole increases. In this state, the shaft is fitted into the shaft hole whose diameter has been expanded. Thereafter, when the headed bolt is screwed back, the diameter of the shaft hole is allowed to be reduced by the elasticity of the hub, and the shaft and the hub are connected.

Further, the expanding operation portion may be a split groove having a female screw extending in a radial direction of the at least one hub, and the female screw may be formed of the split groove from an outer peripheral surface of the at least one hub. It may be formed in a part of the way.

With the above configuration, when the push screw screwed into the female screw of the split groove of the at least one hub is screwed to the end of the female screw and screwed in beyond the end, the shaft hole expands. Diameter. In this state, the shaft is fitted into the shaft hole whose diameter has been expanded. Thereafter, when the push screw is screwed back, the diameter of the shaft hole is allowed to be reduced by the elasticity of the at least one hub, and the shaft and the at least one hub are connected.

The perspective view of the shaft coupling of a 1st embodiment. FIG. 2 is an exploded perspective view of the shaft coupling of FIG. 1. The figure which shows the state before connecting a shaft to the hub of the shaft coupling of FIG. FIG. 4 is a diagram showing a state where a headed bolt is screwed into the hub of FIG. 3. FIG. 5 is an enlarged view of a portion surrounded by a two-dot chain line circle in FIG. 4. The figure which shows the state which connected the shaft to the hub of FIG. The figure which shows the state before connecting a shaft to the hub of the shaft coupling of 2nd Embodiment. The figure which shows the state which screwed the push screw to the hub of FIG. FIG. 9 is an enlarged view of a portion surrounded by a two-dot chain line circle in FIG. 8. The figure which shows the state which connected the shaft to the hub of FIG.

(1st Embodiment)
A shaft coupling according to an embodiment will be described with reference to FIGS.
The shaft coupling 10 has

hubs

20A and 20B. Since the

hubs

20A and 20B have the same structure, the configuration of one hub 20A will be described for convenience of description. In the hub 20B, the same components as those of the hub 20A are denoted by the reference numerals obtained by adding 100 to the reference numerals assigned to the hub 20A, and the description is omitted. The hub 20A corresponds to a driving hub, and the hub 20B corresponds to a driven hub.

ハブ As shown in FIGS. 1 and 2, the hub 20A is made of metal and formed in a ring shape so as to have a shaft hole 22 at the center. The drive shaft 200 can be fitted into the shaft hole 22 of the hub 20A. The driven shaft 300 can be fitted into the shaft hole 122 of the hub 20B.

The hub 20A is formed with a pair of bolt through-holes 24 that are located on the opposite sides of the shaft hole 22 by 180 degrees from each other. The hub 20A is formed with a pair of female screws 26 that are 90 degrees out of phase with the bolt through-holes 24 with the shaft hole 22 interposed therebetween and that are 180 degrees opposite to each other.

The hub 20A and the hub 20B are connected (coupled) to each other by the plurality of fastening bolts 38 in a state where the phases are rotated by 90 degrees with respect to each other. A plurality of washers 32 inserted into the fastening bolts 3 and a plurality of circular ring-shaped leaf springs 34 are sandwiched between the hub 20A and the hub 20B. The plurality of fastening bolts 38 are passed through the bolt through

holes

24, 124 and screwed to the corresponding

female screws

26, 126. The leaf spring 34 and the fastening bolt 38 constitute a rotation transmission unit.

As shown in FIG. 2, an interference avoiding hole 36 is formed at the center of the leaf spring 34. The drive shaft 200 and the driven shaft 300 are inserted into the interference avoiding holes 36 to avoid interference with the leaf spring 34.

ボルト Further, a bolt through hole 40 through which the screw shaft portion of the fastening bolt 38 penetrates is formed in the leaf spring 34. Thus, the

hubs

20A and 20B are connected to each other via the plurality of leaf springs 34 so as to be able to transmit torque.

割り A split groove 30 is formed in the hub 20 A and extends in the radial direction and serves as a widening operation portion that communicates with the shaft hole 22. The split groove 30 is formed at a position that does not interfere with the bolt through hole 24, the female screw 26, and the bolt through hole 40 of one of the leaf springs 34 located proximally in the circumferential direction of the hub 20 A. The split groove 30 is provided over the entire width of the hub 20A in the axial direction. The split groove 30 extends in the radial direction of the hub 20A from the inner peripheral surface of the shaft hole 22 to the outer peripheral portion of the hub. A female screw 31 is formed in the split groove 30 throughout the radial direction of the hub 20A.

In a state where a head bolt 50 described later is not screwed into the female screw of the split groove 30, the inner diameter of the shaft hole 22 of the hub 20 A is larger than the outer diameter of the end fitted to the shaft hole 22 of the drive shaft 200. Is also small. The ridge diameter and valley diameter of the female screw 31 formed in the split groove 30 are set to be screwable with the valley diameter and ridge diameter of the headed bolt 50 described later.

As an external operation, when the headed bolt 50 is screwed into the female screw 31, the head 51 of the headed bolt 50 comes into contact with the outer peripheral surface of the hub 20A. Thereafter, when the external operation in the screwing direction is continued, the crests 31a and 50a of the mutually abutting threads engage with each other (see FIGS. 4 and 5), so that the crest on the side of the split groove 30 is relatively headed. It is pulled to the 51 side. At the same time, a force acts in the direction of increasing the groove width of the split groove 30.

That is, the groove width of the split groove 30 is increased against the elastic force of the hub 20A, and the inner diameter of the shaft hole 22 is expanded to a size in which the end of the drive shaft 200 can be fitted. The head bolt 50 corresponds to an external operation member.

Similarly, in the shaft hole 122 of the hub 20B, the inner diameter of the shaft hole 122 of the hub 20B is set in a state in which the later-described headed bolt 50 is not screwed into the female screw 131 of the split groove 130 as the expanding operation portion. Is smaller than the outer diameter of the end to which the driven shaft 300 is fitted. Further, the ridge diameter and valley diameter of the female screw 131 formed in the split groove 130 are set so as to be screwable with the valley diameter and the ridge diameter of the headed bolt 50 described later.

(4) As an external operation, when the headed bolt 50 is screwed into the female screw 131, the head 51 of the headed bolt 50 comes into contact with the outer peripheral surface of the hub 20B. Thereafter, when the external operation in the screwing direction is continued, the crests on the split groove 30 side are relatively pulled toward the head 51 by the engagement between the

screw threads

131a and 50a that abut against each other. At the same time, a force acts in a direction to increase the groove width of the split groove 130. That is, the groove width of the split groove 130 is increased against the elastic force of the hub 20B, and the inner diameter of the shaft hole 122 is increased to a size that allows the end of the driven shaft 300 to be fitted.

On the other hand, when the corresponding headed bolt 50 is removed from the

split grooves

30 and 130 by an external operation, the inner diameters of the shaft holes 22 and 122 of the

hubs

20A and 20B are reduced by elasticity. Thus, the shaft holes 22 and 122 are fitted with the inserted drive shaft 200 and driven shaft 300, respectively. That is, the hubs 20 A and 20 B tighten the drive shaft 200 and the driven shaft 300 inserted into the shaft holes 22 and 122, respectively, by reducing the inner diameters of the shaft holes 22 and 122 by the elastic force. As described above, since the

hubs

20A and 20B are fitted to the drive shaft 200 and the driven shaft 300 so as not to be relatively movable, the drive shaft 200 and the driven shaft 300 do not fall off from the hub 20A and the hub 20B during use. Is suppressed.

(Operation of First Embodiment)
A method of connecting the drive shaft 200 and the driven shaft 300 to the shaft coupling 10 configured as described above will be described.

In the state shown in FIG. 3, the

hubs

20A and 20B of the shaft coupling 10 are not connected to the drive shaft 200 and the driven shaft 300, and the head bolts 50 are not screwed into the

split grooves

30 and 130.
From this state, when attaching the drive shaft 200 to the hub 20A of the shaft coupling 10, as shown in FIG. 3, the female head 31 of the split groove 30 of the hub 20A is screwed with the headed bolt 50 by an external operation. Combine. After the head 51 of the headed bolt 50 comes into contact with the opening peripheral edge 31b of the female screw 31 on the outer peripheral surface of the hub 20A (see FIGS. 4 and 5), when the screwing is continued, the groove width of the split groove 30 is increased. Is enlarged. Due to the expansion of the groove width, the inner diameter of the shaft hole 22 is elastically expanded to a size in which the end of the drive shaft 200 can be fitted. This diameter expansion is performed until the diameter of the shaft hole 22 becomes large enough to insert the drive shaft 200. The opening peripheral edge 31b corresponds to a locking edge.

(4) After the diameter of the shaft hole 22 is large enough to insert the drive shaft 200, the drive shaft 200 is inserted into the shaft hole 22. Thereafter, the head bolt 50 is screwed away from the female screw of the split groove 30 by an external operation, and the contact between the head 51 and the outer peripheral surface of the hub 20A is released. With this release, the shaft hole 22 is reduced in diameter by the elasticity of the hub 20A. As a result, the drive shaft 200 inserted into the shaft hole 22 fits with the hub 20A (see FIG. 6).

The hub 20A is fitted to the drive shaft 200 by an elastic force. Accordingly, the hub 20A is connected to the drive shaft 200 so as not to be relatively movable, so that the drive shaft 200 does not fall off from the hub 20A during use.

The case where the driven shaft 300 is attached to the hub 20B of the shaft coupling 10 is the same as the case where the drive shaft 200 is attached to the hub 20A. That is, in the above description, the hub 20A is the hub 20B, the drive shaft 200 is the driven shaft 300, the shaft hole 22 is the shaft hole 122, the split groove 30 is the split groove 130, and the female screw 31 is the female screw 131. Just read it. Note that the opening peripheral edge 131b corresponds to a locking edge.

結果 As a result, the drive shaft 200 and the driven shaft 300 can be integrally connected to the

hubs

20A and 20B of the shaft coupling 10 so as not to rotate relatively without leaving the headed bolt 50 in the shaft coupling 10.

Further, after the drive shaft 200 and the driven shaft 300 are integrally fastened (coupled) to the hub, the drive shaft 200 and the driven shaft 300 do not have a fastening screw (bolt). The connection between the shaft 300 and the hub of the shaft coupling is not loosened.

ハブ Furthermore, the

hubs

20A, 20B, the drive shaft 200, and the driven shaft 300 can be connected and released, respectively, only by retreating the head bolt 50. Therefore, the workability of connecting and releasing the hub 20A and the drive shaft 200 and connecting and releasing the hub 20B and the driven shaft 300 can be improved.

This embodiment has the following features.
(1) The shaft coupling 10 of the present embodiment includes a hub 20A (drive hub) having a shaft hole 22 into which the drive shaft 200 fits, and a hub 20B (driven hub) having a shaft hole 122 into which the driven shaft 300 fits. And a rotation transmission unit that transmits rotation between the hubs.

The hub 20A is provided with a split groove 30 (expansion operating portion) that expands the diameter of the shaft hole 22 by an external operation and allows the diameter of the shaft hole 22 to be reduced by the elasticity of the hub 20A after the external operation is released. Further, the hub 20B (the driven hub) expands the diameter of the shaft hole 122 by an external operation, and after the external operation is released, the split groove 130 (expansion operating portion) that allows the diameter of the shaft hole 122 to be reduced by the elasticity of the hub 20B. ).

According to the present embodiment as described above, there is an effect that the fastening of the shaft coupling to the hub is not loosened to the shaft even when vibration is applied during use.
(2) The shaft coupling 10 of the present embodiment includes the

split grooves

30 and 130 as the expanding operation portions. The

split grooves

30 and 130 respectively have

female threads

31 and 131 extending in the radial direction of the

hubs

20A and 20B. Have. As an external operation, the head bolts 50 (male screws) are screwed into the

female screws

31 and 131 of the

split grooves

30 and 130, respectively. As a result, the diameter of the shaft holes 22 and 122 is increased, and after the external operation is released, that is, after the screwing of the headed bolt 50 (male screw) into the

split grooves

30 and 130 is released, the shaft holes 22 and 122 are removed. Reduced diameter was allowed.

As a result, when the head bolts 50 are screwed into the

female screws

31 and 131 of the shaft holes 22 and 122, the widths of the

split grooves

30 and 130 are enlarged and the diameters of the shaft holes 22 and 122 are increased. The drive shaft 200 and the driven shaft 300 can be easily inserted into the diametered shaft holes 22 and 122, respectively. After the screwing of the head bolt 50 into the

split grooves

30 and 130 is released, the diameters of the shaft holes 22 and 122 are allowed, and the drive shaft 200 and the driven shaft 300 are Each can be easily connected and fixed.

In addition, while securing the shaft by friction that does not damage the surface of the shaft (drive shaft, driven shaft) fitted into the shaft hole of the hub, the space for the internal thread can be kept to a minimum, so the hub length (thickness) ) Can be reduced.

(3) In the shaft coupling 10 of the present embodiment, the female screw 31 of the hub 20A (drive hub) has an opening peripheral edge 31b (locking edge) with which the head 51 of the headed bolt 50 is locked. The head bolt 50 is a male screw that is screwed into the female screw 31.

For this reason, the headed bolt 50 screwed into the female screw 31 of the split groove 30 of the hub 20A (drive hub) is locked to the opening peripheral edge 31b (locking edge), and the headed bolt 50 is further screwed. Then, the groove width of the split groove 30 increases, and the diameter of the shaft hole 22 increases. In this state, the drive shaft 200 is fitted into the shaft hole 22 whose diameter has been increased. Thereafter, when the headed bolt 50 is retracted, the diameter of the shaft hole 22 is allowed to be reduced by the elasticity of the hub 20A (drive hub), and the drive shaft 200 and the hub 20A can be connected.

Further, according to the present embodiment, it is sufficient that the hub has a thickness enough to have the opening peripheral edge 31b (locking edge) with which the head 51 of the headed bolt 50 is locked. Can be

(4) In the shaft coupling 10 of the present embodiment, the female screw 131 of the hub 20B (the driven hub) has an opening peripheral edge 131b (an engagement edge) with which the head 51 of the headed bolt 50 is engaged. The head bolt 50 is a male screw that is screwed into the female screw 131.

Therefore, the headed bolt 50 screwed into the female screw 131 of the split groove 130 of the hub 20B (the driven hub) is locked to the opening peripheral edge 131b (locking edge), and the headed bolt 50 is further screwed. Then, the diameter of the shaft hole 122 increases. In this state, the driven shaft 300 is fitted into the shaft hole 122 whose diameter has been expanded. Thereafter, when the headed bolt 50 is screwed back, the diameter of the shaft hole 122 is permitted by the elasticity of the hub 20B, and the driven shaft 300 and the hub 20B can be connected.

(2nd Embodiment)
Next, a shaft coupling 10 according to a second embodiment will be described with reference to FIGS. In the first embodiment, the

split grooves

30 and 130 are provided with

female screws

31 and 131 throughout the radial direction, and the headed bolt 50 can be screwed to the

female screws

31 and 131.

On the other hand, in the shaft coupling 10 of the second embodiment, the

split grooves

30 and 130 have female females in the radial direction of the

hubs

20A and 20B, respectively, in a part of the way from the outer peripheral surface to the shaft holes 22 and 122. The difference is that screws 31 and 131 are provided, and the set screw 52 can be screwed to the

female screws

31 and 131.

のため Apart from this difference, the configuration of the second embodiment is the same as that of the first embodiment, and therefore, the same reference numerals as those of the first embodiment are used and the detailed description is omitted. A hexagonal hole (not shown) for operation is formed on the base end surface of the push screw 52.

(Operation of Second Embodiment)
The operation of the shaft coupling 10 configured as described above will be described.
As shown in FIG. 7, when the push screw 52 is not screwed into the female screw of the split groove 30, the inner diameter of the shaft hole 22 of the hub 20 A is the end of the drive shaft 200 fitted into the shaft hole 22. Is smaller than the outer diameter of

Then, when the push screw 52 is screwed into the female screw 31 and reaches the end of the female screw 31 and is further screwed in, the threads 31a and 50a of the mutually abutting threads are engaged with each other (FIG. 8). And FIG. 9), a force acts in a direction to increase the groove width of the split groove 30.

That is, the groove width of the split groove 30 is increased against the elastic force of the hub 20A, and the inner diameter of the shaft hole 22 is increased to a size in which the end of the drive shaft 200 can be fitted. The push screw 52 corresponds to an external operation member.

(4) After the diameter of the shaft hole 22 is large enough to insert the drive shaft 200, the drive shaft 200 is inserted into the shaft hole 22. Thereafter, the push screw 52 is removed from the position beyond the end of the female screw 31 of the split groove 30 by an external operation, and the push screw 52 is removed from the female screw 31.

押し When the push screw 52 retreats from a position beyond the end of the female screw 31, the hub 20A is elastic and the shaft hole 22 is reduced in diameter. As a result, the drive shaft 200 inserted into the shaft hole 22 fits with the hub 20A (see FIG. 10).

Also in the present embodiment, when the shaft hole 22 and the drive shaft 200 are fitted, the hub 20A is fitted with the drive shaft 200 by elastic force. Accordingly, the hub 20A is integrally connected to the drive shaft 200 so as not to be relatively movable, so that the drive shaft 200 does not fall off from the hub 20A during use.

The case where the driven shaft 300 is attached to the hub 20B of the shaft coupling 10 is the same as the case where the drive shaft 200 is attached to the hub 20A. That is, in the above description, the hub 20A is replaced with the hub 20B, the drive shaft 200 is replaced with the driven shaft 300, the shaft hole 22 is replaced with the shaft hole 122, the split groove 30 is replaced with the split groove 130, and the female screw 31 is replaced with the female screw 131. Just do it.

As a result, the drive shaft 200 and the driven shaft 300 can be integrally connected to the

hubs

20A and 20B of the shaft coupling 10 so as not to rotate relatively without leaving the push screw 52 in the shaft coupling 10. Further, after the drive shaft 200 and the driven shaft 300 are integrally fastened (coupled) to the hub, the drive shaft 200 and the driven shaft 300 do not have a fastening screw (bolt). The connection between the shaft 300 and the hub of the shaft coupling is not loosened.

The connection and release of the

hubs

20A, 20B and the drive shaft 200 and the driven shaft 300 can be performed only by retreating the push screw 52. Workability of connection and release can be improved.

Also in the present embodiment, the hub is fastened by friction that does not damage the surface of the shaft (drive shaft, driven shaft) fitted in the shaft hole of the hub, but at the same time, the securing of the internal thread space can be minimized. Can be reduced in length (thickness).

Further, in the present embodiment, although the push screw 52 is used, the push screw 52 does not come into contact with the shaft fitted into the shaft hole, so that the shaft (the drive shaft and the driven shaft) is connected to the push screw 52. Not be hurt by

The embodiment of the present invention is not limited to the above embodiment, and may be configured as follows.
In the above-described embodiment, the leaf spring 34 has a circular ring shape, but the shape may be arbitrarily changed. For example, the leaf spring 34 may have a square ring shape.

-Each structure described in 1st Embodiment and each structure described in 2nd Embodiment can be combined suitably.
Specifically, for example, the configuration of the hub 20A of the first embodiment may be combined with the configuration of the hub 20B of the second embodiment, or the configuration of the hub 20A of the second embodiment may be combined with the configuration of the hub 20A of the first embodiment. May be combined with the configuration of the hub 20B.

The configuration of the rotation transmission unit is not limited to the leaf spring 34 and the washer 32 of the first and second embodiments, and may be another known configuration.
In the first embodiment, both the

hubs

20A and 20B are provided with the split grooves (expanding operation portions), but only one of the hubs may be provided with the split grooves (expanding operation portions). In this case, the other hub may be connected to the shaft in the same manner as in the related art.

For example, as disclosed in Patent Document 1, a slot is formed in a hub, a bolt hole is formed on one side of the slot, and a screw hole is formed on the other side. Have been. Then, by passing the slit from the side of the bolt through hole and tightening the fastening bolt into the screw hole, the groove width of the slit groove is reduced, the shaft hole diameter is reduced, and the shaft hole is fitted. The tightened shaft is securely fastened to the hub.

In the second embodiment, in the radial direction of the

hubs

20A and 20B, the

female screws

31 and 131 are provided in portions from the outer peripheral surface to the shaft holes 22 and 122, respectively. , 131 can be screwed.

This configuration may be provided only on one of the hubs. In this case, the remaining hub may be connected to the shaft by a method similar to the conventional method, for example, a method described in Patent Document 1 or Patent Document 2.

Claims

Two hubs each having a shaft hole for fitting the shaft,
A rotation transmission unit that transmits rotation between both hubs,
At least one of the two hubs expands the diameter of the shaft hole by an external operation, and after releasing the external operation, expands the elastic hole of the at least one hub to allow the diameter of the shaft hole to be reduced. Having an operation unit,
Shaft coupling.
The shaft coupling according to claim 1, wherein each of the two hubs has the expanding operation portion.
The expanding operation portion is a split groove having a female screw extending in a radial direction of the at least one hub,
The external operation is an operation of screwing a male screw to the female screw of the split groove,
3. The shaft coupling according to claim 1, wherein the release of the external operation is to release a screw engagement of the male screw with the split groove. 4.
The male screw is a headed bolt,
The shaft coupling according to claim 3, wherein the female screw has a locking edge with which a head of the headed bolt is locked.
The expanding operation portion is a split groove having a female screw extending in a radial direction of the at least one hub,
3. The shaft coupling according to claim 1, wherein the female screw is formed in a portion from an outer peripheral surface of the at least one hub to a middle of the split groove. 4.