WO2013049885A1

WO2013049885A1 - A coupler assembly

Info

Publication number: WO2013049885A1
Application number: PCT/AU2012/001200
Authority: WO
Inventors: Leonard John MCINNES
Original assignee: Uniquest Pty Limited
Priority date: 2011-10-04
Filing date: 2012-10-02
Publication date: 2013-04-11

Abstract

A coupler assembly comprising a first coupler member able to be located over a first shaft; a second coupler member able to be located over a second shaft; and a plurality of joining members to join the first coupler member to the second coupler member; a first clamping member able to be located over the first coupler of member to clamp the first coupler of member to the first shaft; and a second clamping member able to be located over the second coupler member to clamp the second coupler member to the second shaft; wherein at least one of the joining members is located within the first clamping member and the second clamping member.

Description

TITLE

"A COUPLER ASSEMBLY"

FIELD OF THE INVENTION

This invention relates to a coupler assembly. In particular, the invention relates to a rigid coupler assembly that is able to be used to connect a shaft of a drive motor to the shaft of a drive pulley of a bulk materials handing conveyor belt. However, it should be appreciated that the coupler assembly may be used to couple any two shafts together.

BACKGROUND OF THE INVENTION

In any bulk materials handing facility, the reliability of the machinery located within the bulk materials handing facility is key to a profitable operation. Any downtime is exceptionally costly. Accordingly, machinery is usually chosen on the basis of its reliability as well as its ease and speed of installation and maintenance. Conveyors often form a core component of a bulk materials handling facility. Therefore failure of a conveyor can slow down or even shut a bulk handling facility which is undesirable.

Rigid couplers are a popular choice of coupling a shaft of a drive motor to a shaft of a drive pulley of a bulk materials handling conveyor belt. The most popular type of rigid coupler is a flange type coupler. Flange type couplers include two flanges which are attached to respective shafts. The flanges are commonly held to the shafts by an associated shrink disc clamp which is located around the flanges and tightened to compress the flange against the shaft. Once the flanges have been attached to the shaft, bolts are located through both flanges to fasten the flanges together and hence the shafts together.

Unfortunately flange type couplers have been known to fail in the field when used on large coal carrying conveyor drives. As stated above, any failure at bulk handling facilities is extremely costly. A coupler failure also presents the risk of large stationary machinery falling from its mount with the possibility of injuring or killing people in the vicinity such as maintenance staff. Accordingly, it has become clear that many flange type couplers are under-designed for applied loads. The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge in Australia.

OBJECT OF THE INVENTION

It is an object of the invention to overcome or alleviate one or more of the above disadvantages or to provide the consumer with a useful or commercial choice.

SUMMARY OF THE INVENTION

In one form, not necessarily the only or broadest form, the invention resides in a coupler assembly comprising:

a first coupler member able to be located over a first shaft;

a second coupler member able to be located over a second shaft; a plurality of joining members to join the first coupler member to the second coupler member;

a first clamping member able to be located over the first coupler of member to clamp the first coupler of member to the first shaft; and

a second clamping member able to be located over the second coupler member to clamp the second coupler member to the second shaft; wherein at least one of the joining members is located within the first clamping member and the second clamping member.

The first coupler member may be in the form of a ring. More preferably, the first coupler member may be in the form of a cylindrical ring. Accordingly, the first coupler member may be a sleeve.

The first coupler member may include a series of joining member apertures. The apertures are normally in the form of joiner holes or joiner slots. The apertures typically extend longitudinally through first coupler member. Further, the apertures normally extend entirely through first coupler member. An end of the apertures may be recessed so that an end of joining members is located within the first coupler member.

A series of voids may be located within the first coupler member. The voids may reduce the radial stiffness of the first coupler member. The voids may be in the form of channels. The voids may be connected to the apertures of the first coupler member. The voids may extend from the apertures to an outer periphery of the first coupler member and/or an inner periphery of the first coupler member. Preferably the voids alternate from extending from the apertures to an outer periphery of the first coupler member to extending from the apertures to an inner periphery of the first coupler member.

An end of the first coupler member may include a rate of change of stiffness portion. The rate of change of stiffness portion may reduce the rate of change of stiffness between the first shaft and the first coupler member.

The rate of change of stiffness portion may include a recess. The recess may be located at an end of the first coupler member between the apertures and an inner periphery of the first coupler member. The recess may be arcuate in cross-sectional shape. The recess may be circular.

The rate of change of stiffness portion may include a tapered portion. The tapered portion may extend from adjacent an inner periphery of the first coupler member to a location before the joining member apertures. The tapered portion may be tapered from adjacent an inner periphery of the first coupler member toward a middle of the first coupler member.

The second coupler member may be in the form of a ring. More preferably, the second coupler member may be in the form of a cylindrical ring. Accordingly, the second coupler member may be a sleeve.

The second coupler member may include a series of joining member apertures. The apertures are normally in the form of joiner holes or joiner slots. The apertures typically extend longitudinally through the second coupler member. Further, the apertures normally extend entirely through the second coupler member. An end of the apertures may be recessed so that an end of a joining member is located within the first coupler member.

A series of voids may be located within the second coupler member. The voids may reduce the radial stiffness of the first coupler member. The voids may be in the form of channels.

The voids may be connected to the apertures of the second coupler member. The voids may extend from the apertures to an outer periphery of the first coupler member and/or an inner periphery of the second coupler member. Preferably the voids alternate from extending from the apertures to an outer periphery of the second coupler member to extending from the apertures to an inner periphery of the second coupler member.

An end of the second coupler member may include a rate of change of stiffness portion. The rate of change of stiffness portion may reduce the rate of change of stiffness between the second shaft and the second coupler member.

The rate of change of stiffness portion may include a recess. The recess may be located at an end of the second coupler member between the apertures and an inner periphery of the second coupler member. The recess may be arcuate in cross-sectional shape. The recess may be circular.

The rate of change of stiffness portion may include a tapered portion. The tapered portion may extend from adjacent an inner periphery of the second coupler member to a location before the joining member apertures. The tapered portion may be tapered from adjacent an inner periphery of the second coupler member toward a middle of the second coupler member.

An alignment portion may be located on the first coupler member and second coupler member to align the first coupler and the second coupler. The alignment portion may be in the form of a spigot located at the end of the first coupler member with associated indentation located in an end of the second coupler member. Alternatively, the alignment portion may include or be a series of dowel holes located at an end of the first coupler member and a series of dowel holes located at an end of the second coupler member with dowels being located in the dowel holes.

Normally the first coupler member and the second coupler member are of substantially the same dimensions. Accordingly, the apertures of the first coupler member and the apertures of the second coupler member are in alignment when in use. It should be appreciated that the dimensions of the first coupler member may be varied with respect to the second coupler member - typically to couple two shafts of different sizes. However, it should also be appreciated that in this instance the apertures of the first coupler member and the apertures of the second coupler member will still be in alignment when in use.

The first coupler member and second coupler member may include torque transmission members to assist in transmission of torque between the first coupler member and the second coupler member. The torque transmission members may be of any form that prevents rotation of the first coupler member with respect to the second coupler member. Normally the torque transmission members include a series of interengaging members.

It would be appreciated by a person skilled in the art that the alignment portion and the torque transmission members may be the same.

The first clamping member and second clamping member may be in the form a shrink disc clamp. However, it should be appreciated by a personal skilled in the art that other types of clamps are likely to be suitable.

The joining members may be in the form of tensioning members. Preferably, the joining members may be in the form of bolts with associated nuts.

The joining members may be pre-fitted within one of the coupler members. However, normally, the joining members are separate to the coupler members.

The joining members may be located inside or surround the first clamping member and the second clamping member. ⁽

In another form, the invention resides in a coupler unit for a coupler assembly, the coupler unit comprising:

a first coupler member able to be located over a first shaft;

wherein the first coupler member is in the form of a sleeve.

Preferably the second coupler member is also in the form of a sleeve. In yet another form, the invention resides in a method of coupling two shafts together using a coupler assembly, the method including the steps of: locating a first coupler member over a first shaft; attaching a first clamping member to the first coupler of member to clamp the first coupler member to the first shaft;

locating a second coupler member able to be located over a second shaft;

attaching a second clamping member to the second coupler member to clamp the second coupler member to the second shaft;

locating a plurality of joining members through the first coupler member and through the second coupler member to join the first coupler member to the second coupler member.

The method may further include the one or more of the following steps:

locating a plurality of joining members into the apertures of the first coupler member; and/or

bringing together the first and second shafts to which the first coupler member and second coupler members are attached such that the plurality of joining members are inserted through the corresponding apertures in the second coupler member.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiment of the invention, by way of example only, will now be described with reference to accompanying drawings in which:

FIG. 1 is a cross-sectional side view of a coupler assembly coupling two shafts together according to an embodiment of the invention;

FIG. 2 is an exploded perspective view of the coupler assembly of FIG. 1 according to an embodiment of the invention;

FIG. 3 is a perspective view of an alternative first coupler member according to an embodiment of the invention;

FIGS 4A to AC are cross-sectional side view of alternate ends of a first coupler member according to an embodiment of the invention;

FIG. 5A is a perspective view of alternate coupler members according to an embodiment of the invention; and

FIG. 5B is a perspective view of s second coupler member according to FIG. 5A. FIG. 6 is a cross-sectional side view of a coupler assembly coupling showing alternative joining members;

FIG. 7 is an exploded perspective view of the coupler assembly using alternative coupler members;

FIG. 8A is a perspective view of alternate coupler members according to an embodiment of the invention;

FIG. 8B is a sectional view of alternate coupler members according to FIG. 8A; and

FIG. 8C is a perspective view of second coupler member according to FIG. 8A.

DETAILED DESCRIPTION OF THE PREFERRED EMBDOIMENT FIG. 1 and 2 show a coupler assembly 10 for coupling a first shaft 20 to a second shaft 30. The coupler assembly 10 includes a first coupler member 40, a second coupler member 50, a series of joining members 60, a first clamping member 70 and a second clamping member 80.

The first coupler member 40 is in the form of a hollow cylindrical ring that is able to be fitted onto the first shaft 20. That is, the first coupler member is a sleeve which is able to be located over the first shaft 20. A series of joining holes 41 pass through the first coupler member 40 and extend from one end of the first coupler member 40 to the other end of the first coupler member 40.

A channel 42 is associated with each of the joining holes 41. The channel extends from an outer periphery 43 of the first coupler member 40 to the joining holes 41 in some of the joining holes 41 whilst a channel 42 extends from the inner periphery 44 of the first coupler member 40 to the joining holes 41 in the other of the joining holes 41. The channels 42 alternate from extending from a joining hole 41 to the outer periphery 43 to the inner periphery 44 extending from a joining hole. The channels 42 reduce the radial stiffness of the first coupler member 40.

A recess 45 is located at the end of the first coupler member 40 between the joining holes 41 and in the inner periphery 44 of the first coupler member 40. The recess 45 is arcuate in transverse cross-section and is circular in shape. This recess 45 is also able to reduce the rate of change of bending stiffness from the shaft member 20 to the coupler member 40.

The first coupler member 40 and second coupler member 50 are similar. The second coupler member 50 is in the form of a hollow cylindrical ring that is able to be fitted onto the second shaft 30. That is, the second coupler member 51 is a sleeve which is able to be located over the second shaft 30. A series of joining holes 51 pass through the second coupler member 50 and extend from one end of the second coupler member 50 to the other end of the second coupler member 50.

A channel 52 is associated with each of the joining holes 51. The channel 52 extends from an outer periphery 53 of the second coupler member 50 to the joining hole 51 in some of the joining holes 51 whilst a channel 52 extends from the inner periphery 54 of the second coupler member 50 to the joining holes 51 in the other of the joining holes 51. The channels 52 alternate from extending to the outer periphery 53 to the inner periphery 54. The channels 52 reduce the circumferential stiffness of the second coupler member 52.

A recess 55 is located at the end of the second coupler member 50 between the joining holes 51 and the inner periphery 54 of the second coupler member 50. The recess 55 is arcuate in transverse cross-section and is circular in shape. This recess 55 is to reduce the rate of change of stiffness from the shaft 30 to the coupler member 50.

The first coupler member 40 includes a spigot 46 located at one end of the coupler member with an associated indentation 56 located at an end of the second coupler member 50. The spigot 46 of the first coupler member

40 is sized to fit neatly within the indentation 56 in the second coupler member 50.

The first clamping member 70 and the second clamping member 80 are both in the form of shrink disc clamps 90. Each shrink disc clamp 90 includes two shrink discs 91 and an associated backing ring 92. A series of shrink disc bolts 93 are able to be located through one of the shrink discs 91 and threaded into the other of the shrink discs 91 to pull the shrink discs 91 toward to each other causing the backing ring 92 to reduce in size.

The joining members 60 are in the form of elongated joiner bolts 61 that have associated washers 62 and nuts 63. The choice of joiner bolts will be dependent on design of the coupler assembly.

In order to coupler the two shafts 20, 30 together using the coupler assembly 10, the first coupler member 40 is located over the first shaft 20. A shrink disc clamp 90 is located over the first coupler member 40 and the shrink disc bolts 93 located through the shrink discs 91. The shrink disc bolts 93 are then tightened to cause the shrink discs 93 to move closer to each other causing the backing plate 92 to apply force to the first coupler member 40. This in turn causes the first coupler member 40 to clamp to the first shaft 20 holding the first coupler member 40 to the first shaft 20. The above process is then repeated for the second coupler member 50 after it has been placed on the second shaft 20.

Once the first coupler member 40 and second coupler member 50 are firmly fixed to their respective shafts 20, 30, the joiner bolts 61 are located through the joiner holes 41, 51 of respective coupler members 40, 50. When coupling short shafts the joiner bolts 61 must be located through the joiner holes 41 of the first coupler member 40 before the first coupler member 40 is located on the first shaft 20. Short shafts are such that insufficient access space is available to insert the long joiner bolts 61 into the joiner holes 41 , 51 when the coupler members are already attached to the shafts. Washers 62 are then placed over respective joiner bolts 61 and associated nuts are screwed on to respective joiner bolts. The tightening of the nuts 63 on the bolts couples the first coupler member 40 and second coupler member 50 together. Therefore, the joiner bolts 61 pass within the confines of the first and second clamping members 70, 80. The alignment of the first coupler member 40 with the second coupler member is facilitated by the spigot 46 of the first coupler member 40 becoming located within the indentation 56 of the second coupler member 50. Once the joiner bolts 61 are tightened the coupler assembly 10 is completed.

The coupler assembly 10 of the present invention is specifically designed to transmit large bending loads in rotational bending. The design of the coupler members 40, 50 have virtuall no change in transverse cross- section throughout the length of the coupler members 40, 50 enables the coupler members 40, 50 to be almost entirely in compression in use. Further, once the coupler members 40, 50 are attached to the shafts 20, 30, the coupler assembly creates a tri-axial compressive stress state in which the coupler assembly can bear high loads while being resistant to distortion or failure.

The coupler assembly 10 provides a number of other advantages including:

• a smaller and shorter coupler compared to traditional flange couplers

• the coupler members are relatively easy to manufacture as they can be constructed using hollow or solid bar stock; and

• the coupler members require no specialist facilities (such as forging) for manufacture with low set up costs.

FIG. 3 shows an alternative first coupler member 40 and second coupler member 50. The coupler members 40,50 in this embodiment shows the joiner holes 41 , 51 have been replaced with joiner slots 47, 57. This allows for joiner bolts 61 to be placed into the joiner slots 47,57 from the side as opposed to an end of the coupler members 40,50.

FIG. 4A to 4C show alternate ends of the first coupler member 40 which have all be designed to reduce the rate of change of stiffness between the shaft and the first coupler member 40. It would be appreciated by a person skilled in the art that the second coupler member 50 may be designed in the same manner.

FIG. 4A shows an end of the first coupler member having two tapers 48 and 49. The first taper 48 extends from adjacent the inner periphery 44 of the first coupler member 40 to adjacent the joiner holes 41. The first taper 48 is inclined from an adjacent the inner periphery 44 of the first coupler member 40 toward a middle of the first coupler member 40. The second taper 49 extends from adjacent the joiner holes 41 to adjacent the outer periphery of the first coupler member 40. The first taper 48 is inclined from an adjacent the joiner holes 41 of the first coupler member 40 toward a middle of the first coupler member 40.

FIG. 4B shows a joiner hole 41 which has an end that has been recessed. The recess end 41 A of the joiner hole 41 is used to seat a head of the bolt 61 so that the bolt 61 is located within the first coupler member 40. It should be appreciated that a similar recessed end on the second coupler member may used to seat the washer and nut. The recessed end 41 A may assist with reducing the rate of change of stiffness between the respective shaft and the respective coupler member.

FIG. 4C shows how the tapers 48 and 49 can be combined with a recess 45 to reduce the rate of change of stiffness between the first shaft 20 and the first coupler member 40. It would be apparent to a person skilled in the art how alternative ends could be produced to reduce the rate of change of stiffness between a shaft 20, 30 and a coupler member 40, 50. .

FIG. 5A and 5B show a first coupler member 40 and a second coupler member 50 that have torque transmission members 100. It would be appreciated by a person skilled in the art that the torque transmission members 100 will also enable alignment between the first coupler member 40 and the second coupler member 50.

In this embodiment the torque transmission members 100 are in the form of cavities 101 and protrusions 02 located at the end of the first coupler member 40 with associated cavities 101 and protrusions 102 located in an end of the second coupler member 50. The cavities 101 and protrusions 102 assist in the transmission of torque between the first coupler member 40 and the second coupler member 50. The cavities 101 and protrusions 102 are rotationally symmetrical and are repeated in a similar angular interval to the apertures 41 , 51 thus making the cavities 101 and protrusions 102 on an end of the first coupler member 40 similar to the cavities 101 and protrusions 102 on a corresponding end of the second coupler member 50.

FIG. 6 shows a coupler assembly 10 where alternative joining members 60 have been utilised. The joining members 60 are in the form of threaded rod 64 that has an associated washers 62 and nuts located at each end of the threaded rod 64. This joining member 60 provides more versatility as the joining member 60 can be inserted and removed from either end of the first coupler member 40 and the second coupler member 50.

FIG. 7 shows a coupler assembly 10 which utilises a different first coupler member 40 and second coupler member 50. Both the first coupler member 40 and second coupler member 50 have channels 42 that extend from the outer periphery 44 to the inner periphery 43 of respective coupler members 40, 50. The channels 42 alternate from extending one end of a respective coupler 40, 50 to approximately three-quarters the length of the respective coupler 40, 50 to extending from the opposite one end of a respective coupler 40, 50 to approximately three-quarters the length of the respective coupler 40, 50. Again, the channels 42 reduce the circumferential stiffness of the first coupler member 40.

FIGS 8A to 8C show an alternative first coupler member 50 and second coupler member 40 that utilise dowels 10. The dowelsl 10 is in the form of a sleeve to allow a joining member 60 to pass through the dowel 110. The dowels 110 are inserted into respective joiner holes 41 , 51 which have been enlarged at one end to accept the dowel 110. The dowels 10 provide two main advantages. The first is ensure alignment of the remaining joiner holes 41 and 51. The second is the dowels 110 enable torque transmission between the first couple member 40 and the second coupler member 50.

In this specification, the terms "comprise", "comprises", "comprising" or similar terms are intended to mean a non-exclusive inclusion, such that a system, method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

It should be appreciated that various other changes and modifications may be made to the embodiment described without departing from the spirit or scope of the invention.

Claims

CLAIMS:

1. A coupler assembly comprising:

a first coupler member able to be located over a first shaft;

2. The coupler assembly of claim 1 wherein the first coupler member is in the form of a ring.

3. The coupler assembly of claim 1 or claim 2 wherein the first coupler member include a series of joining member apertures.

4. The coupler assembly of claim 3 wherein the apertures extend longitudinally through first coupler member.

5. The coupler assembly of claim 3 or claim 4 wherein an end of the apertures is recessed so that an end of the joining members is located within the first coupler member.

6. The coupler assembly of any one of the preceding claims wherein a series of voids are located within the first coupler member.

7. The coupler assembly of any one of the preceding claims wherein an end of the first coupler member includes a rate of change of stiffness portion.

8. The coupler assembly of any one of the preceding claims wherein the second coupler member is in the form of a ring.

9. The coupler assembly of any one of the preceding claims wherein the second coupler member include a series of joining member apertures.

10. The coupler assembly of claim 9 wherein the apertures extend longitudinally through first coupler member.

11. The coupler assembly of claim 9 or claim 10 wherein an end of the apertures is recessed so that an end of the joining members is located within the first coupler member.

12. The coupler assembly of any one of the preceding claims wherein a series of voids is located within the first coupler member.

13. The coupler assembly of any one of the preceding claims wherein an end of the first coupler member includes a rate of change of stiffness portion.

14. The coupler assembly of any one of the preceding claims wherein an alignment portion is located on the first coupler member and second coupler member to align the first coupler and the second coupler.

15. The coupler assembly of any one of the preceding claims wherein the first coupler member and second coupler member include torque transmission members to assist in transmission of torque/ between the first coupler member and the second coupler member.

16. The coupler assembly of any one of the preceding claims wherein the first clamping member and second clamping member are in the form of a shrink disc clamp.

17. The coupler assembly of any one of the preceding claims wherein the joining members are in the form of tensioning members.

18. The coupler assembly of claim 17 wherein the joining members are in the form of bolts with associated nuts.

19. The coupler unit comprising:

a first coupler member able to be located over a first shaft;

wherein the first coupler member is in the form of a sleeve.

20. A method of coupling two shafts together using a coupler assembly, the method including the steps of:

locating a first coupler member over a first shaft;

attaching a first clamping member to the first coupler of member to clamp the first coupler of member to the first shaft;

locating a second coupler member able to be located over a second shaft;

attaching a second clamping member to the second coupler of member to clamp the second coupler of member to the second shaft; attaching a plurality of joining members to the first coupler member and to the second coupler member to join the first coupler member to the second coupler member.