JPH0325652B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a sleeve that spans and covers adjacent ends of two coaxial shafts, and the sleeve is contracted to engage the shafts in a locking manner. The present invention relates to a shaft coupling device. More specifically, liquid is injected between the inner sleeve and the outer sleeve that fit into each other on the tapered surfaces to reduce the frictional resistance between the sleeves, and in this state, the sleeves are moved in the axial direction by the axial drive means. The inner sleeve contracts due to the action of the tapered surface and tightens the adjacent ends of the two shafts, and the outer sleeve maintains its contracted state to connect both shafts. It is something to do. Since the liquid mentioned above is usually oil, this coupling device will hereinafter be referred to as an oil-injected shaft coupling device.
Of course, any suitable liquid can be used to reduce frictional resistance during assembly and disassembly of the coupling device.

In conventionally used oil-injected shaft couplings, the inner sleeve is retracted directly onto both shafts, so that the maximum torque that can be transmitted is determined by the frictional resistance between the retracted inner sleeve and both shafts. In the end, this is largely dependent on the pressure between the shrink sleeve and the two shafts. Therefore, in oil-injected couplings connecting shafts that can operate under high torsional stresses, it has hitherto been difficult to supply the required pressure between the inner and outer sleeves without exceeding the elastic limit of the material of the outer sleeve. To achieve this, it was necessary to make the outer sleeve unacceptably thick. Alternatively, the working length of the coupling device had to be made considerably large.

One of the drawbacks of these solutions is that
The increase in material and manufacturing costs is disproportionately large compared to the coupling efficiency to be achieved. Additionally, solutions that result in an increase in the overall working length of the coupling relative to the shaft surface area are also likely to cause the attendant problem of microslip wear, especially in the direction of rotation. This is even more noticeable when the values change alternately.
Increasing the strength of the material used for the coupling device, ie increasing the limit of the applied stress, makes it possible to limit the maximum dimensions of the coupling device.
However, it also has the disadvantage of increasing the cost of upgrading the material grade and the manufacturing cost of the coupling device.

Although it is already known to provide an intermediate sleeve between the inner sleeve and both shafts, this arrangement avoids the same problems as with conventional two-sleeve constructions when operating under high torsional stresses. It's something that doesn't exist.

It is therefore an object of the present invention to provide an improved oil-injected shaft coupling device for interconnecting two coaxial shafts, which allows higher torque transmission than conventional types of the same size. It's about doing.

The shaft coupling device provided by the present invention is an oil-injected shaft coupling device that interconnects two coaxial shafts;
(b) an inner sleeve that is tightly fitted at a tapered surface with the outer sleeve so as to be held in a contracted state inside the outer sleeve; ) the deflated inner sleeve and the second
a split sleeve, which comprises a plurality of substantially rigid split members interposed under pressure between the two shafts, each of which extends in the axial direction so as to cover the connecting portion of the two shafts; (d) axial drive means for relatively moving the inner sleeve and the outer sleeve in the axial direction in a direction in which the interference fit occurs when the shaft coupling device is installed;
(e) a liquid injection passage provided in either the inner sleeve or the outer sleeve, into which a liquid is injected to reduce frictional resistance between the two sleeves during attachment or detachment of the shaft coupling device; characterized in that at least a part of the torque transmitted by the coupling device during operation is transmitted directly through the split sleeve without passing through the inner sleeve and the outer sleeve.

The reason why the shaft coupling device according to the present invention is able to transmit higher torque than conventional coupling devices of similar size is that there is no compressive stress in the circumferential direction in the aforementioned split sleeve. ,
All forces acting on the outer circumferential surface of the split sleeve are transferred to the surfaces of both shafts. The relationship between circumferential, radial and compressive stresses in couplings using rigid intermediate sleeves results in some loss of contact pressure on both shafts; There isn't.

In the coupling device according to the present invention, it is preferable that the area of the surface of each divided member that is in contact with the inner surface of the inner sleeve is considerably larger than the area of the surface of the divided member that is in contact with both shafts. , so that the pressure between the dividing member and both shafts is greater than the pressure between the inner sleeve and the dividing member. In this split sleeve, there is no compressive stress in the circumferential direction, so
When the radial pressure acting on the outer surface of the split sleeve is transmitted to both shafts, it is increased in proportion to the outer surface area of the split sleeve relative to the surface area of the hole in the split sleeve. The increase in pressure can also be described as being directly proportional to the ratio of the outer diameter of the split sleeve to the inner diameter of the bore. Thus, the split sleeve is useful when transmitting loads exerted by the outer sleeve on the inner sleeve to both shafts.
It actually acts as a kind of pressure amplification medium. This also makes it possible to realize an outer sleeve for the coupling device with an ideal cross-section from both the viewpoints of efficiency and cost.

A further advantage of the present invention is that oil-injected shaft connections for use with connection shafts capable of transmitting high torsional stresses can be of standard design and size. Additional benefits include lower costs and easier procurement of spare parts.

In the shaft coupling device according to the present invention, the split sleeve includes a cylindrical hole formed by a grouping of the split cylindrical portions of the split member and a tapered hole portion formed by a group of arcuate tapered portions of the split member. This is desirable. The inner surface of the cylindrical hole is in contact with both shafts, and the inner surface of the tapered hole is smoothly connected to the inner surface of one end of the cylindrical hole at the end with the smaller inner diameter. .
As a result, when assembling the present coupling device on two shafts that are not originally aligned, the outer and inner sleeves are positioned so as to cover both adjacent ends of the shafts, and the dividing member is placed inside the inner sleeve. By forcibly inserting the two shafts from one end, the two shafts are positioned in line with each other, and at this time, the tapered portions of each split member act as wedges to pull the adjacent ends of both shafts in line. All you have to do is arrange it.

The above divided sleeve has three or more pieces,
Preferably, it is formed by dividing members that are identical and are vertically divided along substantially axial planes. The maximum number of dividing members commonly used is
It should be determined by the manufacturing cost and the operability during installation and removal of the coupling device. Additionally, if the split member is relatively long, it may be desirable to provide one or more axial slots in its outer surface to reduce its radial stiffness.

Said dividing members are separated from each other by a separating member made of an elastic or easily deformable material, so that they may not come into direct face-to-face contact during assembly or operation of the device. It is desirable to ensure that the resulting circumferential compressive stresses are eliminated.
The spacing member may be a length of circular cross-section rubber cord, such as those used in "O" rings. It is also possible for each dividing member to include a length of rubber cord fitted into a slot formed in one axially extending side. The separating member may also be a strip of elastic material adhered to one or more of the axially extending sides of each segment.

From the viewpoint of ease of assembly or disassembly on both coaxial shafts, it is desirable that this coupling device be attached to the inner hole of the inner sleeve, with each divided member maintaining the form of a divided sleeve in relation to each other. For this purpose, each split member may be provided with a radially projecting flange at one end and an external thread at the other end, in which case an inner sleeve is provided at one end of each split member. It is sandwiched between the flange and the nut screwed into the male threaded portion at the other end.

An example of an oil-injected shaft coupling device according to the present invention for interconnecting two shafts will be described below.
A detailed explanation will be given with reference to the attached drawings.

The shaft coupling device includes an outer metal sleeve 10 and an inner metal sleeve 11 which is an interference fit inside the outer sleeve 10.
0 and 11 cover the mutually adjacent ends of the two coaxial shafts 12 and 13. The device further includes a metal split sleeve 14, which is sandwiched between the inner sleeve 11 and the shafts 12,13. Both shafts 12, 13 have the same diameter and abut each other at their respective ends.

As further shown in FIG. 3, the split sleeve 14 has a reduced diameter section 18 at one end thereof having an external thread 19 and an axial slot 20.
is formed. Further, the other end has an annular flange 21 projecting outward in the radial direction.
is provided. The small diameter portion 18 and the adjacent portion of the large diameter portion of the split sleeve 14 are provided with a tapered hole portion 22 inside thereof. The maximum diameter of the tapered hole 22 is slightly larger than the outer diameter of both shafts 12, 13, and is located at the end of the split sleeve 14, and the tapered hole 22 has a maximum diameter slightly larger than the outer diameter of both shafts 12, 13. is equal to the outer diameter of The remaining portion of the split sleeve 14 is
It is provided with a cylindrical hole 23 on its inside having an inner diameter almost equal to the outer diameter of both shafts 12,13.
In this way, the inner circumferential surface of the tapered hole 22 is smoothly connected to the inner circumferential surface of the cylindrical hole 23. The split sleeve 14 is separated by a plurality of axial surfaces and divided into four axially identical split members 24.

The axially extending side surfaces of the dividing members 24 are
The ends of the divided sleeves 14 forming the small diameter portions 18 touch and abut each other. However, one side 25 of each split member 24 is cut longitudinally along the remainder of the split member, as indicated at 26 in FIG. As a result, they are separated from each other over most of the range. An axial slot 28 is cut in the other side 27 of each dividing member 24, into which a long cord 29 made of elastic rubber and having a circular cross section is fitted. code 29
protrudes from the side surface 27 of the dividing member 24. Two axial slots 30 are cut into the outer surface of each split member 24 to reduce the rigidity of the split members 24 in the radial direction.

The inner peripheral surface of the inner split sleeve 11 is cylindrical, and the outer peripheral surface thereof is tapered. The wall thickness of the inner sleeve 11 is the same as that of the outer sleeve 10.
The taper angle is determined so that the wall thickness at the large diameter portion is approximately twice the wall thickness at the small diameter portion. A ring-shaped member 35 is screwed onto the outside of the small diameter end of the inner sleeve.

The outer sleeve 10 has a tapered inner circumferential surface, so that it exactly corresponds to the tapered outer circumferential surface of the inner sleeve 11. At the end of the outer sleeve 10 adjacent to the small diameter end of the inner sleeve 11, an annular recess with a cylindrical wall surface 36 is formed, into which the previously mentioned ring-shaped member 35 can fit. has been done. The inner sleeve 11 and the ring-shaped member 35 cooperate with the recess provided inside the aforementioned outer sleeve 10 to form therein an annular liquid chamber 37, the capacity of which is , outer sleeve 1
0 increases as it moves axially over the inner sleeve 11 away from the ring-shaped member 35, ie towards the larger diameter of the inner sleeve 11.
A port 38 is provided in the wall of the outer sleeve 10 and communicates with the annular liquid chamber 37 . Two further ports 39 are provided in the wall of the outer sleeve 10 and extend through the tapered inner circumference of the sleeve. An annular sealing member 40 made of a piece of rubber or similar elastic material is fixed on one side to the end face of the ring-shaped member 35, thereby forming one wall of the annular liquid chamber 37. ing. In addition, the seal member 4
The inner and outer circumferential surfaces of the ring-shaped member 35 widen as they move away from each other as they move away from the ring-shaped member 35,
This provides liquid tightness to both the inner and outer wall surfaces of the annular liquid chamber 37 in the radial direction.

The divided sleeve 14, which is composed of four divided members 24, is assembled inside the inner sleeve 11 with its annular flange 21 abutting against the large diameter end of the inner sleeve 11. The split sleeve 14 is fixed in position within the inner sleeve 11 by a nut 41 which is threaded onto the external thread 19 and tightens the locking washer 42 against the ring-shaped member 35 on the inner sleeve 11. Locking washer 42 has a key 43 which engages slot 20 previously described. It also has several radial lugs 44, one of which serves to engage one of several slots in the periphery of the nut 41 to lock the nut 41 in place. .

The respective sleeves are properly positioned and fitted around the abutting ends of both shafts 12, 13 as shown in FIG. 1, and then pressurized oil is injected into the inside of the outer sleeve 10 through ports 38, 39. do.
The oil injected from both the ports 39 forms an oil film between the tapered corresponding surfaces of the inner and outer sleeves 11 and 10, reducing the frictional resistance between the sleeves 11 and 10. At the same time, the oil injected into the annular liquid chamber 37 from the port 38 exerts an axial force on the outer sleeve 10, pushing it toward the larger diameter side of the inner sleeve 11. As a result, oil is forced out between the tapered mating surfaces of the inner and outer sleeves 11, 10, and the mating surfaces are brought into direct metal interference contact. The frictional force created between the corresponding surfaces prevents axial movement of the outer sleeve 10 over the inner sleeve 11, so that the outer sleeve 10 holds the inner sleeve 11 in a contracted condition. In this embodiment, the port 39 is connected to the inner sleeve 11.
The port 38 and the annular liquid chamber 37 constitute a liquid injection passage into which oil is injected as a liquid to reduce the frictional resistance between the sleeves 11 and the outer sleeve 10, and the port 38 and the annular liquid chamber 37 move the sleeves 11 and 10 relative to each other in the axial direction. This constitutes an axial drive means for tightly fitting the two.

This shaft connection connects pressurized oil to port 3.
The oil is again injected between the respective tapered corresponding surfaces of both sleeves 10 and 11 through 9, and the oil film formed separates both sleeves and is cut off.
The outer sleeve 10 is then pushed towards the smaller diameter part of the inner sleeve 11 by the pressure of the oil acting on the tapered surface. On the other hand, the oil in the annular fluid chamber 37 is preferably drained at a regulated rate, so that the oil in the annular fluid chamber 37 is drained at a certain regulated rate, so that the oil in the annular fluid chamber 37 is discharged at a certain regulated rate, so that the oil in the annular fluid chamber 37 is discharged at a certain regulated rate, so that when the outer sleeve 10 is disengaged from the inner sleeve 11 by the oil film, the oil is removed at a certain rate. Forward movement is inhibited.

In the shaft coupling device described above, the length of the arc on the outer surface of each split member 24 is considerably greater than the length of the arc on the inner surface of the same member, and the split members 24 are connected to each other by rubber cords 29. Since the shafts 12 and 13 are spaced apart from each other and no compressive stress in the circumferential direction acts there, the pressure between the dividing member 24 and both shafts 12 and 13 is reduced by the contraction of the inner sleeve 11.
As a result of the load exerted on the inner sleeve 1
1 and the dividing member 24. Therefore, this shaft coupling device:
This allows for higher torque transmission than in conventional shaft couplings of comparable size in which the inner sleeve retracts directly on both shafts. This is because, in the conventional type, compressive stress in the circumferential direction occurring in the inner sleeve reduces the amplification effect based on the difference in arc length between the outer circumferential surface and the inner circumferential surface of the sleeve.

Furthermore, in the shaft coupling device described above, since the dividing member 24 extends to cover the coupling portion of both shafts, at least a part of the torque to be transmitted by the coupling device passes through both the inner and outer sleeves 11, 10. Split member 2 directly without
It is conveyed through 4.

In such cases where both shafts 12, 13 are already coaxial before the coupling device is attached, the split sleeve 14 is connected to the inner sleeve 11.
It is rather preferable that the split sleeve 14 and the split sleeve 14 are previously positioned and fixed inside the inner sleeve 11 by the nut 41 before being mounted on the shafts 12, 13. However, if it is not possible to place the two shafts 12, 13 exactly in line, the outer sleeve 10 as well as the inner sleeve 11 may be positioned on the shaft in a pre-press-fit or pre-fit position and then the dividing member 24
may be forcibly inserted into a fixed position inside the inner sleeve 11. The tapered portions of the dividing members 24, which cooperate to form the tapered bore 22, then each play the role of a wedge in order to align the ends of the two shafts. When assembling the coupling device in this manner, the nut 41 is not required. However, the nut 41 facilitates handling of the various components when disassembling the coupling device. The nut 41 and the external thread 19 can of course be replaced by other suitable retaining means, such as a spring or a circlip.

[Brief explanation of drawings]

FIG. 1 is an axial cross-sectional view of a shaft coupling device according to an embodiment of the present invention, and is a cross-sectional view taken at - in FIG. 2. FIG. 2 shows an end face of the coupling device, as seen from the direction of arrow A in FIG. 1 (a portion of the device is cut away to show the details of the structure). FIG. 3 is a side view of the split sleeve. FIG. 4 is a view showing the end face of the split sleeve, as seen from the direction of arrow B in FIG. 10: Outer sleeve, 11: Inner sleeve, 1
2, 13: Shaft, 14: Split sleeve, 1
8: Small diameter part, 19: Male thread, 21: Flange,
22: Tapered hole, 23: Cylindrical hole, 24: Divided member, 28: Slot, 29: Cord, 30:
slot, 35: ring-shaped member, 37: annular liquid chamber, 40: sealing member, 41: nut, 42: locking washer.

Claims (1)

[Scope of Claims] 1. A liquid-injected shaft coupling device for interconnecting two coaxial shafts, comprising: (a) an outer sleeve surrounding adjacent ends of the two shafts;
(b) an inner sleeve that is tightly fitted to the outer sleeve at a tapered surface so as to be held in a contracted state inside the outer sleeve; a split sleeve consisting of a plurality of substantially rigid split members interposed under pressure between the shaft and the split sleeve, each of which extends in the axial direction so as to cover the connecting portion of the two shafts; d) an axial drive means for moving the inner sleeve and the outer sleeve relative to each other in the axial direction in the direction in which the interference fit occurs when the shaft coupling device is installed; and (e) the inner sleeve and the outer sleeve a liquid injection passage provided on either one of the sleeves and into which a liquid is injected to reduce frictional resistance between the two sleeves during attachment or detachment of the shaft coupling device; A shaft coupling device characterized in that at least a part of the torque generated by the splitting sleeve is transmitted directly through the split sleeve without passing through the inner sleeve and the outer sleeve. 2. The surface area of the portion of each of the dividing members that contacts the inner circumferential surface of the inner sleeve is larger than the surface area of the portions that contact the shafts, and therefore the pressure between the dividing member and the shafts is Claim 1, characterized in that the pressure between the inner sleeve and the dividing member is greater than the pressure between the inner sleeve and the dividing member.
Shaft coupling device as described in . 3. The split sleeve has a cylindrical hole formed by a collection of split cylindrical parts of the split member, and a tapered hole formed by a collection of arcuate tapered parts of the split member, and the cylindrical hole The inner surface of the cylindrical hole is in contact with both shafts, and the inner surface of the tapered hole smoothly joins the inner surface of one end of the cylindrical hole at the end of its smaller inner diameter so that the When installing the coupling device on two shafts that are not in line with each other, the outer and inner sleeves are positioned so as to cover both adjacent ends of the shafts, and the dividing member is placed inside the inner sleeve at one end thereof. By forcibly inserting the split member from the top, each of the tapered parts of the split member acts as a wedge to properly align the adjacent ends of the two shafts. 3. The shaft coupling device according to item 2. 4. Any one of claims 1 to 3, characterized in that the divided sleeve is divided along the axial plane and divided into three or more divided members of the same size and shape. The shaft coupling device described in Crab. 5. The shaft coupling device according to claim 4, wherein the divided sleeve consists of four divided members. 6. Claims characterized in that each of said dividing members is provided with one or more axial slots in its outer surface, thereby reducing the radial stiffness of said dividing member. The shaft coupling device according to any one of Items 1 to 5. 7. Claims 1 to 6, characterized in that the dividing members are separated from each other by a separating member made of an easily deformable material over most of their longitudinal direction. The shaft coupling device according to any one of paragraphs. 8. A shaft coupling device according to claim 7, characterized in that each of said dividing members is provided with a strip of elastic material on one of its axially extending sides as said separating member. 9. The shaft connection according to claim 8, wherein the strip made of elastic material is disposed in a slot formed in one axially extending side surface of the dividing member. Device. 10. The shaft coupling device according to claim 8, wherein the strip made of elastic material is adhered to one axially extending side surface of the dividing member. 11. Claim characterized in that the split sleeve is incorporated inside the inner sleeve and thus forms an integral assembly with the inner sleeve to facilitate its handling during assembly or disassembly of the shaft coupling device. Range 1 to 10
The shaft coupling device according to any one of paragraphs. 12. At one end of the split sleeve, axial side surfaces extending in the axial direction of adjacent split members abut each other, and the remaining portions of the axial side surfaces are spaced apart from each other. A shaft coupling device according to any one of claims 1 to 11. 13. The holding means is fitted on the outside of the one end of the split sleeve and holds the adjacent axial side surfaces of the split member in a partially abutting state at the one end of the split sleeve. A shaft coupling device according to claim 12. 14. The shaft coupling device of claim 13, wherein said retaining means includes a nut threaded into an external thread formed on said one end of said split sleeve. 15. The other end of the split sleeve is provided with a radially outwardly projecting annular flange, and the inner sleeve is located between the annular flange and the retaining means. A shaft coupling device according to claim 13 or 14.