SE2030257A1 - Flexible Coupling - Google Patents

Abstract

The invention relates to a flexible coupling arranged with a first coupling half with a first shaft, a second coupling half with a second shaft where the first coupling half is arranged with at least two sockets, and that the second coupling half is arranged with at least two sockets, and where a number of rods are arranged in the sockets so that each rod are arrange partly in a socket in the first coupling half and partly in a socket in the second coupling half. The invention further relates to a method of flexible transfer of rotational and axial force.

Description

FLEXIBLE COUPLING TECHNICAL FIELD The invention relates to drive trains and to flexible couplings for joining a driving shaftto a driven shaft, which may be misaligned relative to each other. The invention furtherrelates to a method of flexible transfer of rotational and axial force.

BACKGROUND OF THE INVENTION, PROBLEM AND PRIOR ART When the axes of rotation of a driving and a driven shaft are not in alignment, there area number of possible categories of such misalignment. One may be considered paralleloffset, that is, where the axes are parallel to each other but spaced from one another in atrans-axial direction. Another may be considered angular offset, which is where the axesare not parallel but intersect at an angle, although the axes may lie in parallel planes.The third is misalignment in the axial direction. Numerous coupling devices have been developed to transmit power from or between two such shafts.

Patent document WO 2017/ 175293 Al discloses a coupling with a first coupling half, asecond coupling half, and a central coupling unit. The disclosed invention has limitedcapability to handle axial forces. Furthermore, the disclosed invention discloses a complicated coupling utilizing a central coupling unit.

Further problems addressed by the invention will become clear from the followingdetailed description of the various embodiments.

OBJECT AND FEATURES OF THE INVENTION The present invention relates to a flexible coupling arranged with a first coupling halfwith a first shaft, a second coupling half with a second shaft where the first couplinghalf is arranged with at least two sockets, and that the second coupling half is arrangedwith at least two sockets, and where a number of rods are arranged in the sockets so thateach rod are arrange partly in a socket in the first coupling half and partly in a socket in the second coupling half.

According to further aspects of the improved flexible coupling, provision is made as follows : that a cover, comprising two parts, are arrange, at least partly, around the first coupling half, the second coupling half, and the rods. that for each rod, a threaded shaft, arranged with two sliding washers, two conicalcompression spring, and a nut, are utilized to mount the cover, the first coupling half, the second coupling half, and the rods. that a press plate is arranged to the first coupling half and that a guide for press plate is arranged to the second coupling half that a sliding plate is arrange between the press plate and the guide for press plate. that the sliding plate is made of a polymer. that a thrust bearing is arrange between the press plate and the guide for press plate.

According to further aspects of the invention, the invention also relates to a method offlexible transfer of rotational and axial forces comprising a flexible coupling where thecentre of the flexible coupling comprises a flat surface arrange on the driving side of thecoupling, a predominantly flat surface arranged on the driven side of the coupling and abearing means arranged between the flat surface of the driving side of the coupling and the predominantly flat surface of the driven side of the coupling.

According to further aspects of the method of flexible transfer of rotational and axial force, provision is made as follows: that the bearing means are a polymer arranged in a ring. that the bearing means are a thrust bearing.

ADVANTAGES AND EFFECTS OF THE INVENTION The coupling device of the invention includes a flexible coupling for use in joining adriving member to a driven member, which members may be misaligned. Furthermore the coupling is able to handle axial forces and have low transmission loss.

BRIEF DESCRIPTION OF FIGURES Different embodiments of the invention are described in more detail below with reference to the attached figures.

Fig. l shows a flexible coupling for one embodiment of the invention Fig. 2 shows a flexible coupling for one embodiment of the invention DETAILED DESCRIPTION OF EMBODIMENTS Fig. l shows a flexible coupling l00 in a mounted state according to a first embodimentof the invention. The coupling comprises a first coupling half l and a second couplinghalf 2, the coupling halves l, 2 are preferable made of metal such as aluminium or steel.The first coupling half comprises a first shaft 5 l , the driving shaft, and a first recess 6larranged in the centre of the first coupling half l. The second coupling half 2 comprisesa second shaft 52, the driven shaft, and a second recess 62 arranged in the centre of thesecond coupling half 2. A number of transmission rods 3 are arrange, at least partly, insockets arranged in the coupling halves l, 2. In the figure l two rods 3, 3 " are shown.The number of rods should be at least two, commonly four rods are used. A cover 4 isarrange around the coupling halves l, 2 comprising two separate parts arranged togetherwith an O-ring l0. The coupling halves l, 2, the rods 3, 3 ' ', and the cover 4 are mounted by, for each rod, a threaded shaft 5, arranged with a sliding washer 6, not shown in fig. 1, conical compression spring 13, not shown in fig. 1, and a nut 11. Therods 3, 3 ' ' transfer rotational force from the driving shaft to the driven shaft. The rodsare preferably made of a polymer such as POM or PEEK or other therrnoplastic withhigh stiffiiess. Due to the stiffness low energy loss is experienced with the flexiblecoupling. Rubber could also be arranged as a part of the rods, or surrounding the rods,or arranged at the respective ends of the rods. The rods could thus partly be made ofrubber. As an altemative the rods could be replaced by a bearing such as a groove ball bearing.

The cavity formed by the first recess 61 of the first coupling half 1 and the secondrecess 62 of the second coupling half 2 comprises a press plate 7, a guide for press plate8 and a sliding plate 9. The press plate 7 and the guide for press plate 8 are preferablymade of steel and the sliding plate 9 is preferably made of a polymer such as POM orPEEK. The press plate 7 absorb compressive forces and is arranged with a flat surfacethat allow the sliding plate 9 to allow for angular deviation since a sliding actionbetween the sliding plate 9 and the press plate 7 is allowed. The press plate 7 ispreferably threaded and arranged in the recess 61 if the first coupling half 1, the recessis also threaded to match the threads on the press plate 7. If the flexible coupling is usedin a situation when axial forces occurs, such as, as an example, drilling, frictionwelding, honing, the press plate handles axial forces between the driving shaft and thedriven shaft. Corresponding to the press plate 7, the press plate 8 is arranged in therecess 62 of the second coupling half 2, the press plate 8 is also preferable threaded and arranged in the correspondingly threaded recess 62 of the second coupling half 2.

The press plate 8 is also arrange with a protrusion, preferably partly sphericalprotrusion, to allow the sliding plate 9, that is arrange with a centre hole, to fit theprotrusion. The sliding plate 9, arrange with a hole, fit the protrusion of the press plate 8in a way so that angular displacement is allowed, i.e. the sliding plate 9 could move in relation to the protrusion of press plate 8.

The sliding plate 9 also takes up or in other ways handles compression force acting onthe first shaft 51 and/or the second shaft 52. The sliding plate 9 could also be exchanged to an axial bearing and/or thrust bearing, such as a thrust ball bearing.

Fig. 2 shows a flexible coupling 100 according to a first embodiment. The couplingcomprises a f1rst coupling half 1 and a second coupling half 2. The f1rst coupling halfcomprises a f1rst shaft 51 and a first recess 61, not shown in f1g. 2, arranged in thecentre of the first coupling half 1. The second coupling half 2 comprises a second shaft52 and a second recess 62 arranged in the centre of the second coupling half 2. Anumber of transmission rods 3 are arrange, at least partly, in sockets arranged in thecoupling halves 1, 2. In a first embodiment four rods, 3, 3 ', 3 ' ', 3' ' ', are arrange insockets 21, 22, 23, 24 in the first coupling half 1, and corresponding sockets 31, 32, 33,34 in the second coupling half 2. A cover 4 is arrange around the coupling halves 1, 2comprising two separate parts arranged together with an O-ring 10. The coupling halves1, 2, the rods 3, and the cover 4 are mounted by, for each rods, a threaded shaft 5,arranged with a sliding washer 6, conical compression spring 13, and a nut 11. The four rods 3, 3 ', 3 ' ', 3' ' ' transfer rotational force from the driving shaft to the driven shaft.

When using the flexible coupling a driving means are arrange to the f1rst shaft 51 andthe flexible couplings second shaft 52 is arranged to the arrangement that is driven bythe driving means. The flexible coupling 100 allows for transferring rotational and axialforce to the arrangement that is driven. The arrangement with the rods 3 allows formisalignment between the driving means and the arrangement that is driven. The f1rstcoupling half 1 and the second coupling half 2 is allowed to be moved in relation toeach other in a number of different ways to handle parallel offset, angular offset and misalignment in the axial direction.

Parallel offset is handled by that there is a slight slack or glitch between the rods andrespective socket that allows a parallel offset. To increase the capability to handleparallel offset between the driving shaft and the driven shaft it is preferable to userubber in the rods or surrounding the rods. Depending upon the parallel offset the slackcould be adjusted to allow for more parallel offset, by increasing the slack, and to allowfor less parallel offset, by decreasing the slack. The slack is adjusted by the size and/or tolerance of the rods outer dimension and the respective sockets intemal dimension.

Angular offset is handled by that the compression springs 13 allows the f1rst couplinghalf 1 and the second coupling half 2, by the rods 3, 3', 3", 3"'sockets 21, 22, 23, 24 in the first coupling half 1, and corresponding sockets 31, 32, 33, 34 in the second coupling half 2, to move in angular direction in relation to each other. , ability to move in the Misalignment in the axial direction is allowed by the rods 3, 3 ', 3 ' ', 3' ", ability tomove in the sockets 21, 22, 23, 24 in the first coupling half 1, and correspondingsockets 31, 32, 33, 34 in the second coupling half 2 the distance between the first coupling half 1 and the second coupling half 2 could thus be varied.

The flexible coupling 100 where the first coupling half 1 is arranged with a number ofsockets 21, 22, 23, 24, and where the second coupling half 2 is arranged with acorresponding number of sockets 31, 32, 33, 34, and where a number of rods 3, 3 ', 3",3 are arranged in the sockets so that each rod 3, 3 ', 3", 3 are arrange partly in asocket 21, 22, 23, 24 in the first coupling half 1 and partly in a socket 31, 32, 33, 34 inthe second coupling half 2 further solves a technical problem of reducing vibrations inthe coupling compared to conventional flexible couplings since there is a directcoupling, with the rods, between the first and second coupling half and thus the drivingand the driven shaft. The rods are automatically moved or arranged to the centre ofrotation and thus transferring the rotational force between the first coupling half 1 to the second coupling half 2 with no or limited vibrations.

ALTERNATIVE EMBODIMENTS The invention is not limited to the particular embodiments shown but can be varied in different ways within the scope of the patent claims.

The used components in the flexible coupling could be of all commonly known varieties with varying material properties, size, shape or form, and surface treatment.

Claims (1)

1. Flexible coupling arranged with a first coupling half (1) with a first shaft (51), asecond coupling half (2) with a second shaft (52) characterized in that the firstcoupling half (1) is arranged with at least two sockets (21, 22, 23, 24), and thatthe second coupling half (2) is arranged with at least two sockets (31, 32, 33,34), and where a number of rods (3, 3 ', 3 ' ', 3"') are arranged in the sockets sothat each rod (3, 3', 3", 3"') are arrange partly in a socket (21, 22, 23, 24) inthe first coupling half (1) and partly in a socket (31, 32, 33, 34) in the secondcoupling half (2). Flexible coupling according to claim 1 characterized in that a cover (4),comprising two parts, are arrange, at least partly, around the first coupling half(1), the second coupling half (2), and the rods (3, 3', 3", 3"'). Flexible coupling according to claim 2 characterized in that for each rod (3, 3 ',3 ' ', 3' ' '), a threaded shaft (5), arranged with two sliding washers (6), twoconical compression spring (13), and a nut (11), are utilized to mount the cover(4), the first coupling half (1), the second coupling half (2), and the rods (3, 3 ',3", 3") Flexible coupling according to any of the previous claims characterized in that apress plate (7) is arranged to the first coupling half (1) and that a guide for pressplate (8) is arranged to the second coupling half (2). Flexible coupling according to claim 4 characterized in that a sliding plate (9) is arrange between the press plate (7) and the guide for press plate (8). Flexible coupling according to claim 5 characterized in that the sliding plate (9) is made of a polymer. Flexible coupling according to claim 4 characterized in that a thrust bearing (9) is arrange between the press plate (7) and the guide for press plate (8). Method of flexible transfer of rotational and axial forces comprising a flexiblecoupling characterized in that the center of the flexible coupling comprises a flatsurface arrange on the driving side of the coupling, a predominantly flat surface arranged on the driven side of the coupling and a bearing means arranged between the flat surface of the driving side of the coupling and the predoniinantly flat surface of the driven side of the coupling. Method of flexible transfer of rotational and axial force according to c1ain1 8 characterized in that the bearing means are a polynier arranged in a ring. Method of flexible transfer of rotational and axial force according to c1ain1 8characterized in that the bearing n1eans are a thrust bearing.