Technical field

[0001 ] The present invention relates generally to an improved coupling disc. Background art

[0002] In prior art there are multiple solutions for connecting two sides of a rotating arrangement to each other. Examples are axle joints, disc couplings, friction connections, and fixed connections wherein the two side of the rotating arrangement are fixed together in a fixed engagement.

[0003] There are multiple drawbacks with solutions as present in the art especially in relation to rigidity, flexibility, and installation dimensions.

[0004] Fixed engagements between for example an engine and a load have the benefit that the rigidity in the connection is good and the installation dimension is relatively short. However, a fixed engagement provides no flexibility in any direction and thereby demands high precision between the rotating members that are fixed together. For example, if a load is attached to an engine most fixed engagement won't allow any tolerance between the engine and the load. In practice this is a large problem due to that most bearings present tolerances in at least one direction creating some misalignment. The effect if arranged even slightly out of center is that such a bearing is worn much faster than if the alignment was in line.

[0005] To solve the aforementioned problems there are solutions in the prior art addressing flexible couplings without some of the drawbacks as presented above. Such solutions include for example rubber couplings utilizing the flexibility in the material to reduces torque peaks, absorb alignment issues, and flex in all directions necessary. Another solution as known in the prior art are solutions with multiple compression springs holding two metal plates together. The metal plates can move in relation to each other and the force is absorbed by the springs. Such solutions have the drawback that they are relatively weak and can't withstand high torque loads. Yet another solution is conventional coupling disc arrangements wherein three parts, one attaching to a first side of the arrangement, one attaching to a second side of arrangement, and a disc arranged in-between, together constitutes a coupling disc arrangement. Such arrangements have drawbacks, especially in relation to the installation dimensions.

[0006] To increase the rigidity of coupling devices one solution is to increase the amount of material, the size of the springs, or similar. This has the effect that the size of the coupling device increases and thereby increase the installation dimension.

[0007] It is common that bearings at different sides in a rotating arrangement, such as engines and generators, have different tolerances in bearings. This presents an issue due to unwanted load on at least one of the sides in the arrangement. This has the effect that bearings are worn much faster than expected, additional friction in the arrangement eventually breaking the coupling or some other part of the arrangement, and excessive heat generation. Another issue is that flexible couplings of the prior art can't withstand high load, high torque, or long time duration tests. For application areas requiring such properties the only solutions in the prior art has been bulky and heavy coupling arrangements.

Summary of invention

[0008] It would thus be beneficial to provide a solution that addresses the aforementioned problems.

[0009] An object of the present invention is to provide a coupling disc that can withstand high torque.

[0010] Another object of the present invention is to provide a coupling disc that minimize the installation dimension.

[001 1 ] Another object of the present invention is to arrange portions to absorb radial forces, for example forces from radial misalignment.

[0012] Another object of the present invention is to arrange protrusions to absorb radial forces, for example forces from radial misalignment. [0013] Yet another object of the present invention is to absorb radial forces both by protrusions and portions as described herein.

[0014] Another object of the present invention is to provide a coupling disc that provides flexibility in a first rotation direction.

[0015] Another object of the present invention is to provide a coupling disc that provides flexibility in a second rotation direction.

[0016] Another object of the present invention is to provide a coupling disc that provides flexibility in a first and second rotation direction, wherein the flexibility has different spring coefficients in the first and second rotation direction.

[0017] Another object of the present invention is to provide a coupling disc from a single piece of material.

[0018] Another object of the present invention is to provide a coupling disc that absorbs radial misalignment between a first and second rotating member.

[0019] Another object of the present invention is to provide a coupling disc that minimizes the radial load on the first and second rotating members.

[0020] Yet another object of the present invention is to provide a coupling disc that provides flexibility in an axial direction.

[0021 ] Yet another object is to combine all of the above objects into a coupling disk.

[0022] The coupling disc of the present solution provides the advantage that the coupling disc can flex in different directions due to its shape. The flexibility doesn't compromise the rigidity in the construction and the slim design allows for a minimal installation dimension.

[0023] The solution relates to a coupling disc, for example adapted for connecting a load to an engine. The coupling disc comprises first attachment means adapted for fastening a first rotating member to the coupling disc and second attachment means adapted for attaching a second rotating member to the coupling disc. The first and second attachment means are arranged in

substantially the same plane.

[0024] It is one advantage with the present solution that the first and second attachment means are arranged in, or substantially in, the same plane. This allows the installation dimension of the coupling disc to be kept to a minimum.

[0025] According to one embodiment the coupling disc comprise at least two portions extending from the center of the coupling disc to a circumference ring of the coupling disc.

[0026] The coupling disc has portions that extends from the center to a circumference ring. The circumference ring is in one embodiment round to its form and is the outermost part of the disc except for the protrusions wherein the first attachment means are arranged. The portions can have different shape, form, and thickness but it is one advantage that the portions are divided in a way that the disc comprises apertures reducing the weight.

[0027] In another embodiment the circumference ring has a different form than round or circular, such as a triangle or rectangular form.

[0028] It is a further one advantage with the present solution that the apertures allow for the portions to flex providing the coupling disc with a spring functionality in a rotational direction.

[0029] The apertures further enable the coupling disc to in one embodiment flex in other directions, such as an axial direction being perpendicular to the plane of the disc or an alignment offset direction intersecting the plane of the disc.

[0030] According to one embodiment portions are arranged with an angle offset between its intersection point with the center and its intersection point with the circumference ring.

[0031 ] It is one advantage that the portions are arranged with an angle offset between its intersection point at the center and the circumference ring. The offset is in one embodiment the same between each of the portions, in another the offset varies. However, it shall be noted that the coupling disc is adapted for rotating arrangements and thereby is required to be balanced either on its own or within the rotating arrangement.

[0032] In one embodiment a first portion has its intersection point at the outer circumference ring at the same angle offset as a second portion has its

intersection point at the center.

[0033] In one embodiment the second portion has its intersection point at the outer circumference ring at the same angle offset as the third portion has its intersection point at the center.

[0034] It shall be noted that the angle offset in one embodiment can be based from a determined spot on the coupling disc and in another embodiment, be determined relative to one or more portions.

[0035] According to one embodiment the portions comprises at least one curved section in its extension direction.

[0036] According to one embodiment the portions comprise at least two curved sections in its extension direction.

[0037] According to one embodiment the portions is of a substantially S-formed shape.

[0038] It is one advantage with the present solution that different forms of portions provide different properties for the coupling disc. It is a further advantage that the curved portions provide different rotation flexibility in the different rotation directions.

[0039] According to one embodiment the portions extend in a fixed plane.

[0040] It is one advantage with the present solution that all the portions extend in a fixed plane providing a minimal installation dimension. [0041 ] According to one embodiment the surface area of the portions varies along the length of said portions.

[0042] It is one advantage with the present solution that the surface area, could also be explained as the width of the portions in the extension plane of said portions, varies along the length of the portions. The different surface area provides different strengths and flexibility which is utilized in one embodiment of the solution.

[0043] According to one embodiment the surface area of the each of the portions is larger in the area close to the center than in the area close to the circumference ring.

[0044] According to one embodiment the first attachment means are arranged outside of the circumference ring and the second attachment means inside the circumference ring.

[0045] It is one advantage with the present solution that the first attachment means are arranged to attach a first side of a rotation arrangement and the second attachment means are arranged to attach a second side of the rotation

arrangement. This has the effect that the different sides of the rotation

arrangement are attached in the same plane minimizing the installation dimension. It is further one advantage that the distance between the first and second attachment means enables the coupling disc to be flexible in multiple directions, allowing for tolerances in bearings, miss alignments at assembly, and similar issues.

[0046] According to one embodiment the first attachment means are arranged on protrusions of the coupling disc.

[0047] It is one advantage with the present solution that the protrusions enable flexibility in a longitudinal axial direction of the rotation arrangement, i.e. in a direction being substantially perpendicular to the extension plane of the coupling disc. [0048] According to one embodiment the protrusions comprises a formed portion extending in a direction perpendicular to the extension direction of the portions.

[0049] According to one embodiment the coupling disc is formed from a single piece of material.

[0050] According to one embodiment the extension plane of the coupling disc, also herein referred to as the plane, is a plane perpendicular to the extension direction of the first and second rotating members.

[0051 ] According to one embodiment the plane is a plane substantially perpendicular to the extension direction of the first and second rotating members.

[0052] According to one embodiment the portions are non-linear.

[0053] According to one embodiment the portions are non-uniform.

[0054] According to one embodiment the portions have a form comprising two curves each in the extension direction of the portions.

[0055] According to one embodiment the formed portion of the protrusions has a U-form.

[0056] According to one embodiment the formed portion of the protrusions are formed with a U-form in a direction of perpendicular to the extension plane of the coupling disc and after the U-form continues to extend in the extension plane of the coupling disc.

[0057] According to one embodiment the first attachment means are adapted to attach a rotating member with a larger diameter than the second attachment means.

[0058] According to one embodiment a guiding aperture is arranged in the center of the coupling disc. [0059] It is one advantage with the guiding aperture that an axis of a first or second rotating member in one embodiment is aligned via said guiding aperture.

[0060] It is another advantage that the circumference ring in one embodiment facilitates that one of said first and second rotating members is aligned and the guiding aperture facilitates that the other of said first and second rotating members is aligned.

[0061 ] According to one aspect for producing a coupling disc, a coupling disc is formed from a single piece of material to a coupling disc, wherein the production method comprises the steps:

- removing material forming at least two apertures,

- forming at least two protrusions extending outwards from a circumference ring, and

- removing material to form first and second attachment means, wherein the first and second attachment means are arranged in substantially the same plane.

[0062] According to one embodiment the formed apertures have a form creating non-uniform portions extending from the center of the coupling disc towards the circumference of the coupling disc.

[0063] According to one embodiment the multiple formed apertures have the same size and shape.

[0064] According to one embodiment the at least two protrusions are produced with a formed portion.

[0065] According to one embodiment for producing a coupling disc, the coupling disc is a coupling disc as described herein.

Brief description of drawings

[0066] The invention is now described, by way of example, with reference to the accompanying drawings, in which:

[0067] Fig. 1 illustrates a front view of a coupling disc according to one embodiment of the present solution. [0068] Fig. 2 illustrates a typical prior art solution.

[0069] Fig. 3 illustrates the center portion of the coupling disc showing one embodiment of the second attachment means and the guiding aperture.

[0070] Fig. 4 illustrates an isometric view of a coupling disc according to one embodiment of the present solution.

[0071 ] Fig. 5 illustrates one embodiment of a coupling disc attached to a flywheel of a Stirling engine.

[0072] Fig. 6 illustrates a cross section of a coupling disc according to one embodiment of the present solution.

[0073] Fig. 7 illustrates one embodiment of a coupling disc attached to a generator.

Description of embodiments

[0074] In the following, a detailed description of the different embodiments will be described with reference to the appended drawings.

[0075] Briefly the coupling disc relates to a flexible coupling that withstand high torque, is flexible in multiple directions enabling that force is absorbed, and provide a rigid connection between two members of a rotating arrangement. The different embodiment as presented above describes many advantages with the coupling disc. The solution further provides a unique combination when features of the present solution are combined.

[0076] Figure 1 illustrates one embodiment of a coupling disc 1 comprising first attachment means 4 arranged on protrusions 2. The first attachment means 4 are adapted to be attached to a first member of a rotation arrangement, such as a fly wheel of an engine. Figure 1 further illustrates apertures 3 in the coupling disc 1 that forms portions 8 extending from the center of the coupling disc to a

circumference ring 7. The portions 8 in the embodiment as illustrated in figure 1 have two curves in their extension direction and varies in surface area as clearly illustrated in figure 1 . It shall be noted that the portions may have different shapes and forms in different embodiments within the scope of the solution.

[0077] Figure 2 illustrates a prior art solution that is common in the art.

[0078] Figure 3 illustrates a view of the center 6 of the coupling disc 1

comprising second attachment means 5. The number, shape, and form of the attachment means 5 can be different in different embodiments. In one embodiment the center 6 is a guiding aperture adapted to host an axis from a load, such as a generator.

[0079] Figure 4 illustrates an isometric view of a coupling disc 1 where the protrusions 2 are visible showing the formed portion 2a that allows the coupling disc to be flexible in additional directions, such as axial displacement or

misalignment.

[0080] Figure 5 illustrates one embodiment of a coupling disc 1 arranged in a Stirling engine. The coupling disc 1 can in different embodiments be arranged in different form of devices, such as other engines. However, it shall be noted that the coupling disc 1 further can be used for other form of power transmissions than between an engine and a load as well.

[0081 ] Figure 5 further illustrates how the coupling disc 1 in one embodiment fits partly inside a fly wheel and that the protrusions 2 attaches to said fly wheel. The fly wheel could be another sort of device such as a rotating disc, a large axis, or any other form of member in a rotating arrangement. The soluion is beneficial because it minimizes the installation dimension of the coupling device 1 .

Figure 6 illustrates one embodiment of a cross section of a coupling disc 1 wherein the form of the formed portion 2a of the protrusions 2 is clearly visible. It shall be noted that the form of the formed portion 2a can be different in different

embodiments as long as it serves the purpose of absorbing force and/or minimizing the installation depth. The formed portions 2a can for example be U- shaped or have any other suitable shape for absorbing forces in a radial direction of the coupling disc 1 .