A connection device and a machine comprising such connection device

Abstract

The invention relates to a connection device (100) for connecting two components, the connection device comprising: an axle (110); at least one fastening device (130) arranged in connection with the axle; and at least one expansion sleeve (10) arranged on the axle to secure the axle in a hole (4), wherein the axle comprises at least one tapered section (117, 118) and is configured to be arranged with the at least one tapered section in a hole, wherein the at least one expansion sleeve is arranged over the tapered section, the at least one fastening device pressing axially against the expansion sleeve, such that the expansion sleeve expands and an outer wall of the expansion sleeve presses with a sleeve clamping force against an inner wall of the hole, wherein the at least one fastening device comprises at least one force distributing element (132) and at least one fastening element (134) for applying an axial fastening force on the at least one force distributing element, wherein the at least one force distributing element is configured with an axial flexibility.

Description

[0001]A connection device and a machine comprising such connection deviceTECHNICAL FIELDThe present invention relates to a connection device. The invention also relatesto a machine comprising such a connection device. Specifically, the presentinvention relates to a connection device comprising an axle and an expansion sleeve arranged on the axle to secure the axle in a hole. BACKGROUNDThere are many different ways of achieving connection between two machineparts or components. For pivotal connection, typically a hinge journalled inbearings is used, where one or more bearings are arranged on an axle, whichis fixed in holes in a pair of pivot lugs on one of the machine parts and whereinthe bearings are connected to the second machine part. With such arrangement, the relative movement between the bearings and the axle will eventually lead towear, which results in excessive play also between the axle and the pivot lugs.This may damage the axle, which could have serious consequences. The overcome these problems, expansion sleeves arranged between the axle and the pivot lugs may be used. When tightening fastening elements at the ends of the axle, an axial force is applied on the expansion sleeves, the expansionsleeves will expand and apply a sleeve clamping force on the inner walls of thepivot lugs. This way, the axle is secured in the pivot lugs.The expansion sleeve will apply a sleeve clamping force on the inner walls of the pivot lugs and secure the axle as long as there is an axial force on theexpansion sleeve. Due to uneven holes, wear, play and / or material relaxation,the fastening elements of the connection device are often required to be re- tightened in order to ensure enough force applied on the expansion sleeve and thereby achieve a desired clamping force. SUMMARY Despite known solutions in the field, it would be desirable to develop aconnection device, which overcomes or alleviates at least some of thedrawbacks of the prior art.An object of the present invention is thus to achieve a connection device, whichresults in an improved sleeve clamping force. Specifically, an object of thepresent invention is to achieve a connection device, which provides a continuoussleeve clamping force and reduces the need for frequent re-tightening of thefastening element. Furthermore, an object of the present invention is to achievea connection device which is robust, user-friendly and cost-efficient.The herein mentioned objects are achieved by a connection device and amachine comprising such a connection device according to the independentclaims.Hence, according to an aspect of the present invention, a connection device forconnecting two components is provided. The connection device comprises: anaxle; at least one fastening device arranged in connection with the axle; and atleast one expansion sleeve arranged on the axle to secure the axle in a hole, wherein the axle comprises at least one tapered section and is configured to be arranged with the at least one tapered section in a hole, wherein the at least one expansion sleeve is arranged over the tapered section, the at least one fastening device pressing axially against the expansion sleeve, such that the expansion sleeve expands and an outer wall of the expansion sleeve presses with a sleeveclamping force against an inner wall of the hole, wherein the at least onefastening device comprises at least one force distributing element arranged toabut the at least one expansion sleeve, and at least one fastening element forapplying an axial fastening force on the at least one force distributing element,wherein the at least one force distributing element is configured with an axialflexibility. The at least one force distributing element having axial flexibility means that the at least one force distributing element is configured to allow deformation in the axial direction. The at least one force distributing element is configured to be deformed in the axial direction when being subject to the axial fastening force applied by the at least one fastening element. The connection device as disclosed herein may be a pivot pin assembly or a rigid bolt connection. The hole in which the axle is to be secured by means of the expansion sleeve may be a borehole in a component or a lug bore of a pivotlug. The expansion sleeve may thus be configured to be arranged on an axle ofthe connection device to secure the axle (for example a pivot pin) in a pivot lug.When tightening the at least one fastening element, the expansion sleeve is pushed axially over the tapered section of the axle, and the expansion sleeve will expand. The outer wall of the expansion sleeve will this way press againstthe inner wall of the hole and thereby apply a sleeve clamping force.The axle, the expansion sleeve and the at least one force distributing element are collinearly arranged and the axial direction of the at least one force distributing element is aligned with the axial direction of the axle and the expansion sleeve.Commonly known connection devices comprising expansion sleeves typicallycomprises an integrated or a separate flat washer as a force distributing elementto transfer the fastening force from one or more fastening elements to the expansion sleeve. Due to wear, play and material relaxation, the expansion sleeve may after some time no longer provide enough sleeve clamping forceand the axle will be loosely arranged in the hole. To secure the axle, thefastening element will have to be re-tightened periodically to make theexpansion sleeve expand more and thereby maintain the sleeve clamping force.When the fastening element has a smaller outer diameter than the innerdiameter of the expansion sleeve, the transfer of force from the fasteningelement to a flat washer will eventually cause the washer to bend inwards into the expansion sleeve. This way, the force acting on the expansion sleeve willnot only have an axial direction but also include a radial force which will pressagainst the expansion sleeve. The bent washer will act similar to a cone beingpressed down a hole which will try to enlarge the hole. In this case, it means thatthe bent washer will apply a force on the expansion sleeve which force will tryto bend the expansion sleeve edges outwards. This may cause the outer wall ofthe expansion sleeve to abut the outer edge of the hole and negatively affect the expansion capability of the expansion sleeve. With the connection device according to the present invention, the at least one force distributing element willprovide a continuous axial force on the expansion sleeve and an improved andcontinuous sleeve clamping force can thereby be achieved. When the fasteningforce is applied on the at least one force distributing element, the axial flexibilitywill allow a small degree of deformation of the at least one force distributing element. This deformation stores potential energy within the material of the atleast one force distributing element and creates a constant pressure or axialforce against the expansion sleeve. This axial force is maintained as long as theapplied fastening force is present. Thus, the force distributing element havingaxial flexibility ensures that tension is maintained in the connection device and will compensate for loosening caused by wear etc. As wear, play and material relaxation affects the hole and the connection device, the load on the at least one force distributing element will be reduced and the at least one forcedistributing element will try to return to its original shape and energy is released.This flexibility or elasticity will contribute to the continuous force applied on the expansion sleeve. With the connection device according to the present invention, there is thus a reduced risk of the expansion sleeve loosening insidethe hole, and there will be an improved sleeve clamping force against the innerwalls of the hole making the connection device more robust. The connectiondevice according to the invention will eliminate or reduce the need for active re- tightening and will thus be cost-efficient. Furthermore, the at least one forcedistributing element will help distributing the fastening force more evenly acrossthe expansion sleeve. Compared to using a thick flat washer in order to avoid the bending of the washer, the at least one force distributing element according to the invention also requires less material, protrudes less and has less weight. The at least one force distributing element may comprise a spring. The at leastone force distributing element may thus be an elastic object that storesmechanical energy and when it is subject to a force and axially deforms, it exertsan opposing force approximately proportional to the axial deformation. The atleast one force distributing element comprising a spring will store energy when the fastening force is applied and release energy when the force is reduced or removed. The at least one force distributing element is configured to return to its original shape when any load or force on the force distributing element has been removed. The at least one force distributing element comprises at least one opening for the at least one fastening element to pass through the force distributing element. The at least one fastening element may extend through the force distributing element and into the axle.The at least one force distributing element may comprise a disc spring or acompression spring. The at least one force distributing element may comprise a spring washer, a cupped / cup washer, a Belleville washer, a wave spring, a helical spring or similar. The at least one force distributing element may thus be configured with a shape allowing axial flexibility and thus axial deformation. The force distributing element may have an essentially concave or conical shape. In such event, axial deformation of the force distributing element means deflection of the force distributing element. The force distributing element is typically arranged such that the convex side abuts the fastening element and the concave side abuts the expansion sleeve. The force distribution element may have acentral dome or a cup-like depression surrounded by an outer rim. This shapeallows it to deform under pressure or load. The applied fastening force thuscauses the force distributing element to flatten out. Alternatively, the forcedistributing element may have an essentially helical shape. In such event, axial deformation of the force distributing element means compression of the helical force distributing element. In some examples, the at least one fastening device may comprise a flat washer arranged between the at least one fasteningelement and the force distributing element having a helical shape. This isbecause the fastening element typically has a smaller outer diameter than the inner diameter of such force distributing element.The at least one force distributing element is typically configured such that itapplies a force on the expansion sleeve only in the axial direction when the atleast one fastening element applies the fastening force. The at least one forcedistributing element being configured to allow axial deformation means that it only will apply an axial force on the expansion sleeve. This way, no radial forces will act on the walls of the expansion sleeve and the sleeve clamping force willbe improved. The force distributing element is thus configured to avoid radialforces on the expansion sleeve.In one example, the at least one fastening device comprises a plurality of force distributing elements arranged in a stack. Specifically, in the event that the force distributing element comprises a disc spring or a Belleville washer, multiple forcedistributing elements can be stacked in series to achieve a desired force on theexpansion sleeve. Stacking force distributing elements allows for an increase in the overall loadcapacity of the connection device. Each additional force distributing element inthe stack contributes to the spring force, enabling the stack to handle higherloads compared to a single force distributing element. Arranging multiple forcedistributing elements in a stack will also affect the stiffness of the arrangementand the stiffness can be easily adjusted by adding or removing force distributingelements. Furthermore, having multiple force distributing elements in a stack willprovide redundancy in case one force distributing element fails, breaks ordeforms. Stacking force distributing elements also ensures a more uniformdistribution of force across the entire stack. Stacking provides flexibility in designing the connection device with specific spring characteristics to meet therequirements of a particular application. Thus, by stacking multiple forcedistributing elements one can achieve a desired load and / or axial deformation(compression or deflection) of the force distributing elements.It is to be understood that the force distributing elements arranged in a stackmay be identical or they may be configured differently. Thus, the fasteningdevice may comprise force distributing elements of different sizes and thicknesses in a stack. This enables modularity and flexibility in that the connection device can be customized for various applications. The stacked force distribution elements may be arranged with alternating orientation or the force distributing elements may be stacked in the same orientation. Alternating the orientation of the stacked force distributing elements can enhance stability and reduce the risk of buckling or tilting. Alternatingorientations may also result in a more even distribution of loads throughout thestack. This way, localized stress concentrations on specific force distributing elements may be avoided and the overall durability of the connection device can be improved. Arranging the force distribution elements with the same orientationin a stack, on the other hand, simplifies the design and assembly process andmakes it easier to predict and calculate the stacks spring rate and load capacity.Force distributing elements in the same orientation also contribute to a moreuniform and predictable stiffness throughout the stack. It will also be easier to replace a force distributing element in the stack if all force distributing elements have the same orientation. In one example, the at least one fastening device comprises a plurality of fastening elements arranged to apply a fastening force on a common force distributing element. Such arrangement allows the use of wedge-lock washers to secure the fastening elements. A larger force distributing element can be used instead of using multiple force distributing elements, and thus fewer parts are required which will facilitate assembly. Also, the fastening device will protrude less. In another example, the at least one fastening device comprises a plurality of fastening elements and a plurality of force distributing elements, one arrangedin association with each fastening element. This will add redundancy to thefastening device and thus increase the robustness of the connection device.The at least one fastening element may comprise a nut or a bolt. The at leastone fastening element may be arranged surrounding an end section of the axleor it may be partly inserted into the axle. The expansion sleeve may have a tapering inner wall. This means that the expansion sleeve may comprise an inner diameter, which varies along the axial extension of the expansion sleeve. The tapering inner wall may be tapering in direction towards the at least one fastening device pressing against the expansion sleeve. Thus, the inner diameter of the expansion sleeve may increase in direction away from the at least one fastening device. According to another example, the tapering inner wall of the expansion sleeve has a length similar to, or shorter than, a length of the tapered section of the axle. The tapering inner wall may thus have the same length as the tapered section of the axle or be shorter than the tapered section of the axle. In one example, the axle comprises a first end and a second end and the connection device comprises two fastening devices, one arranged at each end of the axle, wherein the axle further comprises a centre section, a first tapered section tapering from the centre section towards the first end, and a secondtapered section tapering from the centre section towards the second end. Thecentre section typically has a circular cross-section along the whole axial extension of the centre section. The tapered sections of the axle may have an axial extension similar to the width of the holes. The length (axial extension) of the centre section of the axle may thus correspond to the distance between the two holes. The connection device may comprise two expansion sleeves, one arranged at each tapered section of the axle.According to yet another aspect of the present invention, a machine is provided,the machine comprising a connection device as disclosed herein to connect twocomponents. The hole(s) into which the axle and the expansion sleeve is to bearranged form part of one of the components to be connected to each other by means of the connection device. The second component may be connected to the centre section of the axle of the connection device. The present disclosure is applicable on all sorts of components being connected. The present disclosure is applicable on all bolt / pin / axle connections for fixating or aligning components, both pivotal connections and rigid connections. The disclosure is applicable on any types of machines or equipment, for example construction vehicles, mining vehicle, forestry vehicles or similar. Further objects, advantages and novel features of the present invention will become apparent to one skilled in the art from the following details, and also by putting the invention into practice. Whereas the invention is described below, it should be noted that it is not restricted to the specific details described. Specialists having access to the teachings herein will recognise further applications, modifications and incorporations within other fields, which are within the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGSFor fuller understanding of the present disclosure and further objects andadvantages of it, the detailed description set out below should be read together with the accompanying drawings, in which the same reference notations denote similar items in the various drawings, and in which:Figures 1a-b schematically illustrate a connection device anddetails of a connection device according to anexample;Figure 2a-b schematically illustrate a connection device anddetails of a connection device according to anexample;Figure 3a-b schematically illustrate connection devices accordingto two examples;Figures 4a-b schematically illustrate a connection device accordingto an example;Figures 5a-b schematically illustrate a connection device accordingto an example; andFigure 6 schematically illustrates a machine according to anexample. DETAILED DESCRIPTIONThe present disclosure will now be further illustrated with reference to theappended figures.Figures 1a-b schematically illustrates a connection device 100 and details of aconnection device 100 according to an example of the present disclosure. Figure1a shows the connection device 100. The connection device 100 comprises anaxle 110; at least one fastening device 130 arranged in connection with the axle110; and at least one expansion sleeve 10 arranged on the axle 110 to securethe axle 110 in a hole 4. The hole 4 is in this example a lug bore in a pivot lug.The axle 110 comprises a first end 112 and a second end 114 and the connection device 100 comprises two fastening devices 130, one arranged at each end of the axle 110. The axle 110 further comprises a centre section 116, a first tapered section 117 tapering from the centre section 116 towards the first end 112, and a second tapered section 118 tapering from the centre section 116 towards the second end 114. The connection device 100 further comprises two expansion sleeves 10, one arranged at each tapered section 117, 118 of the axle 110.The expansion sleeves 10 are arranged over the tapered sections 117, 118 andthe fastening devices 130 are pressing axially against the expansion sleeves 10,such that the expansion sleeves 10 expand and an outer wall of the expansionsleeves 10 presses with a sleeve clamping force against an inner wall of theholes 4.The fastening devices 130 each comprises a force distributing element 132arranged to abut the at least one expansion sleeve 10, and a fastening element134 for applying an axial fastening force on the force distributing element 132and thus the at least one expansion sleeve 10. The fastening elements 134 arebolts.The force distributing elements 132 are each configured with an axial flexibility.In this example, the force distributing elements 132, as shown in Figure 1b, aredisc springs and thus have a conical or concave shape allowing axial flexibilityand thus axial deformation. When the fastening element 134 applies a fastening force on the force distributing element 132, the force distributing element 132will deflect and store energy. The force distributing elements 132 will this wayprovide a continuous axial force on the expansion sleeves 10, which thereby will provide a continuous sleeve clamping force against the inner walls of the holes4. The force distributing elements 132 are here arranged such that the convexside abuts the fastening elements 134 and the concave side abuts theexpansion sleeves 10. Figures 2a-b schematically illustrates a connection device 100 and details of a connection device 100 according to an example of the present disclosure. Figure2a shows the connection device 100. The connection device 100 may be configured as in Figure 1a with exception for the fastening devices 130. In this example, the fastening devices 130 each comprises a force distributing element 132, a fastening element 134 and a flat washer 136.The force distributing elements 132 are each configured with an axial flexibility.In this example, the force distributing elements 132, as shown in Figure 2b, arecompression springs and thus has a helical shape allowing axial flexibility anddeformation. When the fastening element 134 applies a fastening force on the force distributing element 132, the force distributing element 132 will becompressed and store energy. The force distributing elements 132 will this wayprovide a continuous axial force on the expansion sleeves 10, which thereby will provide a continuous sleeve clamping force against the inner walls of the holes4. The flat washer 136 of each fastening device 130 is arranged between thefastening element 134 and the force distributing element 132 because the fastening element 134 has a smaller outer diameter than the inner diameter ofthe force distributing element 132. The flat washer 136 thus has a largerdiameter than the inner diameter of the force distributing element 132. Figures 3a-b schematically illustrate connection devices 100 according to twoexamples. The connection device 100 may be configured as in Figure 1a but inthese examples, the fastening device 130 comprises a plurality of forcedistributing elements 132 arranged in a stack. Specifically, in these examplesthere are three force distributing elements 132 arranged in a stack but it is to beunderstood that the fastening devices 130 could comprise any number of forcedistributing elements 132. The force distributing elements 132 comprise discsprings. Figure 3a shows the force distributing elements 132 arranged in a stack with alternating orientation, whereas Figure 3b shows the force distributing elements 132 arranged in a stack in the same orientation. It is to be understood that even if these figures show identical force distributing elements 132 in thestacks, they could be differently configured.Figures 4a-b schematically illustrate a connection device 100 according to anexample of the present disclosure. The connection device 100 may beconfigured as in any of Figure 1a, 2a, 3a or 3b with exception of the fasteningdevice 130. In this example, each fastening device 130 comprises a plurality offastening elements 134 arranged to apply a fastening force on a common force distributing element 132. The fastening device 130 also comprises a flat washer 136 arranged between the force distributing element 132 and the fasteningelements 134. Thus, the multiple fastening elements 136 are all passing throughthe flat washer 136 and the force distributing element 132 and into the axle 110. The flat washer 136 has a larger outer diameter than the inner diameter of the force distributing element 132. The sole force distributing element 132 is arranged to abut the expansion sleeve 10 and the fastening force from the fastening elements 134 is transferred to the force distributing element 132 via the flat washer 136. Figures 5a-b schematically illustrate a connection device 100 according to an example of the present disclosure. The connection device 100 may be configured as in any of Figure 1a, 2a, 3a or 3b with exception of the fasteningdevice. In this example, each fastening device 130 comprises a plurality offastening elements 134 and a plurality of force distributing elements 132, onearranged in association with each fastening element 134.In this example, the expansion sleeve 10 comprises an essentially flat end plate 10’ and the force distributing elements 132 are arranged to abut said end plate 10’. The fastening devices 134 each extends through the force distributing element 132, the end plate 10’ of the expansion sleeve 10 and into the axle 110. The figure shows three fastening elements 134 with a respective force distributing element 132. The force distributing elements 132 and the fastening elements 134 are typically arranged such that at least a part of each force distributing element 132 is aligned with the outer periphery of the end plate 10’.Figure 6 schematically illustrates a machine 1 according to an example of thepresent disclosure. The machine 1 is in this example a vehicle. The vehicle 1may be a construction vehicle, a mining vehicle or a forestry vehicle. The vehicle1 comprises a connection device 100 as disclosed in Figure 1a, 2a, 3a, 3b, 4a-b, or 5a-b. The vehicle 1 comprises two components 2, 3, which are connectedby means of the connection device 100. One of the components 2, 3 comprisesa hole 4 into which the connection device 100 is inserted. The other component2, 3 may be connected to the centre section 116 of the axle 110 of theconnection device 100.The foregoing description of the examples of the present disclosure is providedfor illustrative and descriptive purposes. It is not intended to be exhaustive or torestrict the disclosure to the variants described. Many modifications andvariations will obviously be apparent to one skilled in the art. The examples havebeen chosen and described in order best to explain the principles of thedisclosure and its practical applications and hence make it possible forspecialists to understand the disclosure for various examples and with thevarious modifications appropriate to the intended use.

Claims

Claims 1. A connection device (100) for connecting two components (2, 3), the connection device (100) comprising: an axle (110); at least one fastening device (130) arranged in connection with the axle (110); and at least one expansion sleeve (10) arranged on the axle (110) tosecure the axle (110) in a hole (4), wherein the axle (110) comprises at least one tapered section (117, 118) and is configured to be arranged with the at least one tapered section (117, 118) in a hole (4), wherein the at least one expansion sleeve (10) is arranged over the tapered section (117, 118), the at least one fastening device (130) pressing axially against the expansion sleeve (10), such that the expansion sleeve (10) expands and an outer wall of the expansion sleeve (10) presses with a sleeve clamping force against an inner wall of the hole (4), wherein the at least one fastening device (130) comprises at least one force distributing element (132) arranged to abut the at least one expansion sleeve (10), and at least one fastening element (134) for applying an axial fastening force on the at least one force distributing element (132),characterized in that the at least one force distributing element (132) isconfigured with an axial flexibility.

2. The connection device (100) according to claim 1, wherein the at least one force distributing element (132) comprises a spring.

3. The connection device (100) according to claim 2, wherein the at least one force distributing element (132) comprises a disc spring or a compression spring.

4. The connection device (100) according to any one of the preceding claims,wherein the at least force distributing element (132) is configured such that itapplies a force on the expansion sleeve (10) only in the axial direction when the at least one fastening element (134) applies the fastening force.

5. The connection device (100) according to any one of the preceding claims, wherein the at least one fastening device (130) comprises a plurality of force distributing elements (132) arranged in a stack.

6. The connection device (100) according to claim 5, wherein the force distributing elements (132) in the stack are arranged with alternating orientation.

7. The connection device (100) according to any one of the preceding claims, wherein the at least one fastening device (130) comprises a plurality of fastening elements (134) arranged to apply a fastening force on a common force distributing element (132).

8. The connection device (100) according to any one of claims 1-6, wherein the fastening device (130) comprises a plurality of fastening elements (134) and a plurality of force distributing elements (132), one arranged in association with each fastening element (134).

9. The connection device (100) according to any one of the preceding claims, wherein the at least one fastening element (134) comprises a nut or a bolt.

10. The connection device (100) according to any one of the preceding claims, wherein the axle (110) comprises a first end (112) and a second end (114) and the connection device (100) comprises two fastening devices (130), one arranged at each end (112, 114) of the axle (110), wherein the axle (110) further comprises a centre section (116), a first tapered section (117) tapering from the centre section (116) towards the first end (112), and a second tapered section (118) tapering from the centre section (116) towards the second end (114).

11. A machine (1), comprising a connection device (100) according to any one of the preceding claims to connect two components (2, 3) of the machine (1).

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