Device for aiding the insertion of magnets into a hollow shaft

Abstract

There is provided a device (100) for aiding in inserting internal magnets into a hollow shaft (600) and / or removing internal magnets from the hollow shaft, the hollow shaft extending along a longitudinal axis (A-A), the device comprising a fixed member (200) configured to support the hollow shaft, a first magnet (330a) mounted such that, when in a use position, the north pole of the first magnet faces the hollow shaft, and a second magnet (330b) mounted such that, when in a use position, the south pole of the second magnet faces the hollow shaft, wherein the first and second magnets are axially moveable relative to the fixed member. There is also provided a method for inserting internal magnets into a hollow shaft, a method for removing internal magnets from a hollow shaft, and a method for assembling an actuator.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a device for aiding in inserting internal magnets into a hollow shaft and / or removing internal magnets from the hollow shaft and associated methods for inserting and / or removing magnets using the device.BACKGROUND

[0002] Various applications, for example some actuators comprise a hollow shaft in which a plurality of opposing magnets are arranged in series so as to generate a repulsive force between consecutive magnets. Due to these repulsive forces between consecutive magnets, the hollow shaft is not straightforward to fill by simply inserting the magnets therein without further assistance. It is necessary to overcome the repulsive forces so that the hollow shaft can be filled with the required number of magnets.

[0003] There is therefore a need for an improved method of inserting and / or removing internal magnets from a hollow shaft and for a device for aiding in their insertion and / or removal.SUMMARY

[0004] According to a first aspect of the disclosure, there is provided a device for aiding in inserting internal magnets into a hollow shaft and / or removing internal magnets from the hollow shaft, the hollow shaft extending along a longitudinal axis, the device comprising a fixed member configured to support the hollow shaft, a first magnet mounted such that, when in a use position, the north pole of the first magnet faces the hollow shaft, and a second magnet mounted such that, when in a use position, the south pole of the second magnet faces the hollow shaft, wherein the first and second magnets are axially moveable relative to the fixed member.

[0005] In any example of the disclosure, at least one of the first and second magnets may move radially relative to the hollow shaft.

[0006] In any example of the disclosure, the first and second magnets may be configured to be external to the hollow shaft and configured to align with a respective internal magnet of a plurality of axially stacked internal magnets in the hollow shaft.

[0007] In any example of the disclosure, the first and second magnets may be axially offset from each other.

[0008] In any example of the disclosure, the device may comprise a moveable member, wherein the first and second magnets may be mounted on the moveable member and the moveable member may be axially moveable relative to the fixed member so as to move the first and second magnets axially.

[0009] In any example of the disclosure, the device may comprise an insertable member configured to be inserted into the hollow shaft along the longitudinal axis.

[0010] In any example of the disclosure, at least one of the first and second magnets may be a permanent magnet, or wherein at least one of the first and second magnets may be an electromagnet.

[0011] In any example of the disclosure, at least one the first and second magnets may comprise a protective layer configured to protect the hollow shaft against damage caused by contact with the at least one of the first and second magnets.

[0012] In any example of the disclosure, at least one of the first and second magnets may be removeable from the moveable member.

[0013] In any example of the disclosure, the fixed member may comprise a clamp configured to grip the hollow shaft.

[0014] In any example of the disclosure, the fixed member may comprise a flat plate.

[0015] In any example of the disclosure, the fixed member may be adapted to lock the moveable member in position.

[0016] In any example of the disclosure, the fixed member may comprise a clamp configured to lock the moveable member in position.

[0017] In any example of the disclosure, the fixed member may be adapted to allow for discrete indexation of the moveable member.

[0018] In any example of the disclosure, at least one of the fixed member, the moveable member or rotating member is non-magnetic.

[0019] In any example of the disclosure, at least one of the at least first and second magnet may be connected to a respective rod.

[0020] In any example of the disclosure, each rod may be configured to be gripped by a user.

[0021] In any example of the disclosure, the moveable member may comprise each rod.

[0022] In any example of the disclosure, each rod may be configured to be lockable relative to the moveable member.

[0023] In any example of the disclosure, the rods may be angled relative to each other.

[0024] In any example of the disclosure, the rods may be angled radially relative to each other.

[0025] In any example of the disclosure, the insertable member may be elongate.

[0026] In any example of the disclosure, the insertable member may have a handle.

[0027] In any example of the disclosure, the insertable member may have a narrow portion and a wide portion.

[0028] In any example of the disclosure, the insertable member may be fixable relative to the hollow shaft.

[0029] In any example of the disclosure, the insertable member may comprise radial through-holes.

[0030] In any example of the disclosure, the insertable member may comprise radial boreholes.

[0031] In any example of the disclosure, the fixed member may comprise an upward extending member comprising a through-hole configured to align with one of the through-holes of the insertable member.

[0032] In any example of the disclosure, a pin may be received by the upward extending member and at least one of the insertable member through-holes and bores.

[0033] In any example of the disclosure, the protective layer may partially cover the first and second magnet.

[0034] In any example of the disclosure, the protective layer may cover the entire first and second magnet.

[0035] In any example of the disclosure, the protective layer may comprise at least one of elastomeric material, PTFE, PEEK, polymers materials, plastic materials or any other suitable material.

[0036] According to second aspect of the disclosure, there is provided a method for inserting internal magnets into a hollow shaft, the method comprising providing the device of any of the above examples, supporting a hollow shaft in the fixed member, inserting a plurality of internal magnets into the hollow shaft through an open end thereof such that each internal magnet experiences a repulsive force from its neighbour axially along the hollow shaft, simultaneously or subsequently inserting an insertable member into the open end of the hollow shaft, pushing the internal magnets into the hollow shaft with the insertable member, and positioning one of the first and second magnets axially and / or radially relative to the hollow shaft so as to attract the magnet closest to the open end of the hollow shaft, so as to maintain the plurality of internal magnets in position within the hollow shaft when the insertable member is removed.

[0037] In any example of the disclosure, the method may comprise removing the insertable member from the hollow shaft, and inserting a further internal magnet into the hollow shaft.

[0038] According to a third aspect of the disclosure, there is provided a method for removing internal magnets from a hollow shaft, the method comprising providing the device of any of the above examples, supporting a hollow shaft in the fixed member, wherein the hollow shaft comprises a plurality of internal magnets arranged such that each internal magnet experiences a repulsive force from its neighbour in an axial direction along the hollow shaft, and a closing member configured to close an open end of the hollow shaft so as to retain the plurality of internal magnets therein. The method further comprises positioning one of the first and second magnets axially and / or radially relative to the hollow shaft so as to attract the internal magnet closest to the open end of the hollow shaft, so as to maintain the plurality of internal magnets in position when the closing member is removed, removing the closing member, and moving the one of the first and second magnets out of position such that the repulsive force between each neighbouring internal magnet causes each internal magnet to move axially along and out of the hollow shaft.

[0039] In any example of the disclosure, the method may comprise installing a removal member proximal the open end of the hollow shaft, for example after removing the closing member and / or before moving the one of the first and second magnets out of position.

[0040] According to a fourth aspect of the disclosure, there is provided a method of assembling an actuator, the method comprising inserting a plurality of internal magnets into a hollow shaft by the method of any of the above examples, closing the open end of the hollow shaft with a closing member so as to retain the plurality of internal magnets in the hollow shaft; and installing the closed hollow shaft in an actuator.

[0041] In any example of the disclosure, the actuator may be a linear actuator.

[0042] In any example of the disclosure, the method may comprise linking a position sensor to the hollow shaft via the cap.BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various examples will now be described, by way of example only, and with reference to the accompanying drawings in which: Figs. 1A-D show schematic perspective views, taken from different angles, of an insertion device according to an example of the disclosure; Figs. 2A and 2B show plan views, taken from first and second axial ends respectively, of the device of Figure 1A; Figs. 3A and 3B show a cross-sectional view of an insertion device according to an example of the disclosure in two different positions; Figs. 4A-E show a cross-sectional view of an insertion device according to an example of the disclosure during various steps in a process of inserting internal magnets into a hollow shaft; and Fig. 5 shows a cross-sectional view of an insertion device according to an example of the disclosure with a removal sleeve fitted thereon. DETAILED DESCRIPTION

[0044] The present disclosure relates to a device for aiding in inserting internal magnets into a hollow shaft and / or removing internal magnets from a hollow shaft. In some examples, the device may be configured to insert the internal magnets and / or to remove the internal magnets. In other examples, however, the insertion and / or removal of the internal magnets may be done manually or in part manually whilst using a device according to an example of the disclosure. The hollow shaft may form, for example, a rod for use in a linear actuator. In any example, the hollow shaft may define a longitudinal axis and / or may extend along a longitudinal axis. In any example of the disclosure, the device includes a fixed member configured to support the hollow shaft. The fixed member may support the hollow shaft so that the hollow shaft is held or fixed relative to the fixed member. In any example of the disclosure, the device includes a first magnet and a second magnet. The device is configured such that the first and second magnets may move axially, or in other words their position may be adjusted axially, relative to the fixed member. For example, the first and second magnets may move along an axis (as described below) parallel to the longitudinal axis. In any example of the disclosure, the first magnet is mounted such that, when in a use position, the north pole of the first magnet faces the hollow shaft and the second magnet is mounted such that, when in a use position, the south pole of the second magnet faces the hollow shaft.

[0045] With reference to Figs. 1A-D, various perspective views of a device 100 for aiding in inserting internal magnets into and removing internal magnets from a hollow shaft 600 are shown. Figs. 2A and B show views of the device 100 from first and second axial ends thereof, for example top and bottom views thereof, respectively. The hollow shaft 600, which does not form part of the device according to the disclosure, when filled with internal magnets 700, may be used as a rod 340 in a linear actuator. The linear actuator may be used for actuating, for example, flight control surfaces such as horizontal stabilizer elevators and / or rudders in an aircraft.

[0046] In the present example, the device 100 comprises a fixed member 200 configured to support the hollow shaft 600. In the present example, the fixed member 200 comprises a flat plate 210 which may be fixed to a stationary structure such as work bench, for example by a clamp or a vice (as described further below). In the present example, the fixed member 200 comprises an aperture 202 (as seen in Fig. 2A) through which the hollow shaft 600 may extend. In some examples, the aperture 202 is shaped and sized so as to closely match the axial cross-section of the hollow shaft 600, such that the hollow shaft 600 is supported in place. In the present example, the aperture comprises a gripping member. In other examples, the fixed member 200 may be held in place by a clamp or other adjustable mechanism so as to be able to accommodate hollow shafts 600 of different diameters within the device. In such an example, the clamp may comprise gripping material, for example rubber, to enhance the grip.

[0047] In the present example, the hollow shaft 600 defines a first axial end 602 and a second axial end 604. The first axial end 602 is open such that internal magnets 700 can be inserted into and or removed from the hollow shaft 600 therethrough. This is more clearly shown in Figs 3A and B. Figs. 3A and Bshow cross-sectional views of a device 100 according to an example of the disclosure with an insertable member 400 received by the hollow shaft 600. The second axial end 604 comprises a closed end so to retain the internal magnets 700 in the hollow shaft 600. In the present example, the second axial end 604 is closed by a removeable cap 610. By making the cap 610 removeable, the magnets may be easily accessed from either the first axial end 602 or second axial end 604. In some examples, the hollow shaft comprises an internal rib (not shown) configured to engage with the removable cap 610 so as to retain the removable cap 610 in place. In other examples, the second axial end 604 may be closed by a permanent closing member (not shown). That is, second axial end 604 may be closed by a cap 610 that is integral with the hollow shaft 600. Alternatively, the cap 610 may be fixed in place by permanent means (not shown). For example, the cap 610 may be welded, bonded or otherwise fixed to the hollow shaft 600. In any example, the cap 610 may be made from a non-magnetic material, for example, a magnetic steel. In the present example, the hollow shaft 600 defines a longitudinal axis A-A. In the present example, the hollow shaft 600 is elongate with a circular cross-section. In other examples, the hollow shaft 600 may have a different cross-section. For example, the cross-section may be rectangular, oval, pentagonal, hexagonal, or any other n-sided shape.

[0048] In the present example, the hollow shaft 600 may comprise a protective sleeve (not shown). In the present example, the protective sleeve is a thin layer circumferentially surrounding the hollow shaft and is not visible in the drawings. By providing a protective sleeve, the hollow shaft 600 is prevented from being damaged when, for example, being placed in the device 100 and / or prevented from damage by the at least one of the first and second magnets 330a, 330b when the least one of the first and second magnets 330a, 330b are moved into position for use. In the present example, the protective sleeve completely surrounds the circumferential outer surface of the hollow shaft 600. By surrounding the entire circumferential outer surface of the hollow shaft 600, protection is maximised. In other examples, the protective sleeve may surround only portions of the circumferential outer surface of the hollow shaft 600. For example, the first axial end 602 to prevent any damage when placing the hollow shaft 600 in the device 100 and / or the second axial end 604 to prevent damage in case of the hollow shaft 600 slips. The protective sleeve may comprise elastomeric material, PTFE, PEEK, polymers materials, plastic materials and / or any other suitable material.

[0049] In the present example, the fixed member 200 is configured to be gripped by a worktop vice 500. In the present example, this is achieved by the fixed member 200 comprising a block 260 configured to be received by the mouth of the vice 500. In other examples, the fixed member 200 may comprise a series of blocks configured to be received by the mouth of the vice 500. In other examples, the fixed member 200 may comprise other means for securing the device 100 in place for use. For example, the fixed member 200 may comprise a clamp for gripping onto an edge of a worktop or the like. Additionally or alternatively, the fixed member 200 may be configured to receive fastening means, such as screws and / or bolts, for securing the device 100 to a worktop or the like.

[0050] In the present example, the device 100 comprises a moveable member 300, which is axially moveable relative to the fixed member. The first magnet 330a and the second magnet 330b are mounted to the moveable member 300 in the example shown. In other examples, the moveable member 300 may comprise more than two magnets.. In the present example, the first and second magnets 330a, 330b are permanent magnets. However, at least one of the first and second magnets 330a, 330b may be an electromagnet.

[0051] In the present example, the moveable member 300 is configured to move axially relative to the hollow shaft 600 such that the first and second magnets 330a, 330b move axially relative to the hollow shaft 600. Put another way, the moveable member 300 is moveable along an axis parallel to the longitudinal axis of the hollow shaft 600. Since the moveable member 300 comprises the first and second magnets 330a, 330b, the first and second magnets 330a, 330b will also move axially relative to the hollow shaft 600. Put another way, the first and second magnets 330a, 330b are moveable, via the moveable member 300, along an axis parallel to the longitudinal axis of the hollow shaft 600. As will be understood, the moveable member 300 is moveable along its longitudinal axis relative to the fixed member 200.

[0052] In the present example, the fixed member 200 comprises an opening for receiving the moveable member 300 therethrough. In the example shown, the fixed member 200 comprises a tubular member 220 that extends upwardly from the flat plate 210 for receiving the moveable member 300 therethrough, wherein the longitudinal axis of the tubular member 220 is parallel to the longitudinal axis of the hollow shaft 600. The tubular member 220 provides a guiding function so as keep the moveable member 300 parallel to the hollow shaft 600. Additionally or alternatively, the fixed member 200 may be configured to guide the moveable member 300 so as to remain parallel to the hollow shaft 600 in other ways. For example, the opening or otherwise, may comprise a guide rail, for example an inward facing protrusion configured to engage with an axial groove in the outer surface of the moveable member 300. Additionally or alternatively, the moveable member 300 may comprise a guide rail configured to engage with a groove defining a radially recess in the opening. By providing a rail and groove arrangement, the moveable member 300 is prevented from rotating about its longitudinal axis whilst located in the device 100.

[0053] As will be described in more detail below, during use the moveable member 300 may be temporarily fixed relative to the fixed member 200. That is, the device 100 may be configured so as to hold the moveable member 300 in position relative to the fixed member 200 and hollow shaft 600. The fixed member 200 and moveable member 300 may therefore be configured so as to provide axial-indexation (height indexation in some examples) of the moveable member 300. That is, the moveable member 300 may be fixed in place relative to the fixed member 200 at discrete intervals.

[0054] In the present example, the moveable member 300 comprises a series of radial through-holes 310 arranged consecutively in the axial direction. In the present example, the tubular member 220 comprises a radial through-hole. The respective through-holes of the tubular member 220 and the moveable member 300 are configured such that a pin 230 may pass therethrough, thereby fixing the moveable member 300 relative to the fixed member 200. As will be described in more detail below, alignment of the first and second magnets 330a, 330b with internal magnets 700 within the hollow shaft 600 is important. Therefore, by providing height-indexation, the first and second magnets 330a, 330b and internal magnets 700 may readily be aligned. Accordingly, it will be understood that the spacing between consecutive through-holes 310 will depend on the size of the internal magnets 700. In some examples, the through-holes 310 may be bores instead, such that the pin 230 does not extend fully through the moveable member 300, yet will retain the moveable member 300 in place. Additionally or alternatively, the tubular member 220 and / or the opening in the fixed member 200 may comprise a radially extending inward retractable member configured to engage with the through-holes 310 and / or bores. In other examples, the fixed member 200 may comprise means for allowing the moveable member 300 to be fixed in place relative to the fixed member 200 in a continuous manner. That is, the moveable member 300 may be moved axially relative to the hollow shaft 600 and fixed in place at any position, rather than at discrete intervals. For example, the fixed member 200 may comprise a clamp configured to grip the moveable member 300 so retain the moveable member 300 in place relative to the fixed member 200.

[0055] In the present example, the moveable member 300 comprises a rotating member 320 on which the first and second magnets 330a, 330b are provided. In the present example, the rotating member 320 is located at an end of the moveable member 300 and is configured to pivot about the longitudinal axis X-X of the moveable member 300. The rotating member 320 is configured so as to be rotatable towards and away from the hollow shaft 600 in use. That is, the rotating member 320 is configured so as to move the first and second magnets 330a, 330b towards and away from the hollow shaft 600 in use, for example in a direction perpendicular to the longitudinal axis A-A of the hollow shaft 600. Additionally or alternatively, the rotating member 320 may be configured to rotate about a radial axis at an end of the moveable member 300. In any example including a rotating member 320, the rotating member 320 may be fixed in place axially relative to the moveable member 300. By providing a rotating member 320, the first and second magnets 330a, 330b may be easily moved towards and away from the hollow shaft 600 when required in operation and may also be held in a fixed axial position relative to the hollow shaft whilst being moved. In other examples, the intermediate member 320 be configured so as to be permanently axially fixed relative to the moveable member 300. In such an example, the intermediate member 320 may be integral with the moveable member 300 or attached and fixed in place.

[0056] In the present example, the first and second magnets 330a, 330b are configured to move relative to the intermediate member 320 such that in use the first and second magnets 330a, 330b are moveable towards and away from the hollow shaft 600. That is, the first and second magnets 330a, 330b may translate relative to the intermediate member 320 in a direction perpendicular to the longitudinal axis of the moveable member 300. Of course, only one of the first and magnets 300 may move relative to the intermediate member 320. In examples with a rotating member 320, at least one of the first and second magnets 330a, 330b may be fixed relative to the moveable member 300 such that the at least one of the first or second magnet 330a, 330b can only move relative to the hollow shaft 600 by pivoting the rotating member 320.

[0057] In the present example, each of the first and second magnets 330a, 330b are connected to an end of a respective rod 340a, 340b, wherein the rods 340a, 340b extend through the intermediate member 320. In other examples, only one of the first and second magnets 330a, 330b may be connected to an end of a rod. In the present example, the rods 340a, 340b are configured so as to be grippable by a user so as to translate the rods 340a, 340b and the first and second magnets 330a, 330b relative to the intermediate member 320. In the present example, the end of the rods 340a, 340b opposite respective magnets 330a, 330b comprise radially outwardly extending members 342. These radially outwardly extending members 342 make it easier for a user to grip and translate the rod 340a, 340b. Additionally or alternatively, the rods 340a, 340b may comprise texture so as to provide increased grip. For example, the portion of the rod 340a, 340b to be gripped by a user may be integrally textured and / or comprise material to enhance grip e.g. rubber. In some examples, at least one of the first and second magnets 330a, 330b may be entirely removable from the device 100. This allows defective magnets to be replaced and / or magnets to be replaced by magnets with increased or decreased strength which may selected appropriately. In examples with rods 340a, 340b, the rotating member 320 may be configured so as to lock the rods 340a, 340b in place with respect thereto. In the present example, the rods 340a, 340b threadingly engage with the openings in the rotating member 320 so as to screw and be held in place.

[0058] In the present example, the first and second magnets 330a, 330b each comprise a protective layer 350 (see Fig. 2B) configured such that, in use, the first and second magnets 330a, 330b do not directly contact the hollow shaft 600. By providing such a protective layer 350, the hollow shaft 600 is protected from damage if one or both of the first and second magnets 330a, 330b otherwise inadvertently contacted the hollow shaft 600. In the present example, a protective layer 350 is attached to each end of the first and second magnets 330a. 330b opposite the respective rods 340a, 340b and configured so as to complement the shape of the outer circumferential surface of the hollow shaft 600. That is, the protective layer 350 comprises a concave shape so as to be flush with the outer circumferential surface of the hollow shaft 600. By providing a complementary shape, the protective layer 350 provides protection whilst allowing the at least first and second magnet 330a, 330b to be positioned closer to the hollow shaft 600. In other examples, the protective layer may be uniform across the end of the magnets 330a, 330b or partially cover the end of the magnets 330a, 330b. The protective layer may comprise elastomeric material, PTFE, PEEK, polymers materials, plastic materials and / or any other suitable material. Of course, only one of the first and second magnets 300 may comprise a protective layer 350.

[0059] In examples with two or more magnets, each magnet may be connected to respective rods 340a, 340b, and each having any feature described above. In examples with two or more rods 340a, 340b, each rod 340a, 340b may be angled relative to each other. For example, in use, each rod 340a, 340b is circumferentially spaced from the other rods relative to the longitudinal axis of the hollow shaft 600. This is more clearly shown in the plan views of the device 100 in Figs 2A and B. By providing angled rods 340a, 340b, each rod 340a, 340b is more easily accessed by a user. In some figures, one or both of the rods 340a, 340b may not be visible due to the orientation of the device.

[0060] It will be understood that in any example of the disclosure, the position of the first and second magnets 330a, 330b may either be adjusted manually or automatically in both the axial and radial directions.

[0061] In the present example, the device 100 comprises an insertable member 400 configured to be received by the hollow shaft 600 through the opening at the first axial end 602. The insertable member 400 is removeable from the hollow shaft 600. The purpose of the insertable member 400 is to temporarily retain inserted magnets in the hollow shaft 600 whilst at least one of the first and second magnets 330a, 330b is manoeuvred into place. The operation of the device 100 is more clearly described below.

[0062] Figs. 3A and 3B, show a device according to an example of the disclosure, in which a hollow shaft 600 is mounted, into which a series of internal magnets 700 have been inserted. In the present example, the insertable member 400 is elongate and comprises two portions 410 and 420. A first portion 410, which may be referred to as a handle 410, and a second portion 420 configured to be insertable into the hollow shaft 600. In the present example, the handle 410 is configured such that the insertable member 400 cannot be completely inserted into the hollow shaft 600. In the present example, the handle 410 has a radial cross-sectional area greater than the radial cross-sectional area of the second portion 420. This prevents the insertable member 400 being completely inserted into the hollow shaft 600. In this example, the diameter of the radial cross-section of the first portion 410 is greater than that of the second portion 420. In other examples, the insertable member 400 may comprise one or more radially outwardly extending members, for example a protrusion, configured to engage with the first axial end of the hollow shaft 600 so as to prevent the insertable member 400 being completely inserted into the hollow shaft 600. In other examples, such means to prevent complete insertion may be omitted. For example, the handle 410 shown may be omitted. In the present example, the first and second portions 410 and 420 have circular radial cross-sections. In the present example, the diameter of the second portion 420 matches that of the inner diameter of the hollow shaft 600 such that the insertable member 400 is flush within the hollow shaft 600. By providing a flush fit, this risk of the insertable member 400 damaging the interior of the hollow shaft 600 is reduced since lateral movement (e.g. sidewards movement) of the insertable member 400 is minimised, if not completely reduced. In other examples, the second portion 410, that is, the portion insertable into the hollow shaft 600 may have a diameter less than that of the internal diameter of the hollow shaft 600.

[0063] In some examples, the device 100 may be configured so as to retain the insertable member 400 in place when the device 100 is in use. The operation of the device 100 is described in more detail later. In the present example, the insertable member 400 comprises a series of radial through-holes 430 arranged consecutively in the axial direction and each configured to receive a pin 250. This is shown as a similar arrangement to that of the through-holes 310 in the moveable member 300. In the present example, the fixed member 200 comprises an axially (for example upward) extending member 240 from the flat plate 210. In the present example, the upward extending member 240 comprises a radial through-hole configured to receive the pin 250. As will be described in more detail below, the insertable member 400 can be inserted into the hollow shaft 600 so as to temporarily retain the internal magnets 700 therein. This may either be done manually or may be automated. The through-holes 430 of the insertable member 400 and the upward extending member 240 may be aligned as to receive the pin 250, thereby retaining the insertable member 400 in place. As with the moveable member 300, in other examples, the through-holes 430 may instead be bores. In other examples, the fixed member 200 may comprise a clamp configured to clamp the insertable member 400 in place. That is, the insertable member 400 may be inserted to the desired position and subsequently clamped. By providing the clamp, the need to align the above-mentioned through-holes 430 is removed, thereby reducing the operating complexity of the device 100. In any example where the device 100 is configured to retain the insertable member 400 in place, the operating complexity of the device 100 is reduced since a user is not required to hold the insertable member 400 in place whilst operating the rest of the device 100. In some examples, the device 100 may comprise a guide (not shown) configured to guide the insertable member 400 into the hollow shaft 600 rather than relying on the hollow shaft 600 itself being the guide. For example, the fixed member 200 may comprise the guide. Additionally or alternatively, the device 100, or guide if present, may be configured so as to move, translate, swing, or otherwise, the insertable member 400 away from the first axial end of the hollow shaft 600 so as to make the opening more accessible, thereby making it easier to insert internal magnets 700 into the hollow shaft 600.

[0064] In any example, any of the parts of the device 100 may comprise non-magnetic materials. For example, at least one of the fixed member 200, moveable member 300, intermediate member 320 and insertable member 400 may comprise non-magnetic material. The non-magnetic material may be amagnetic steel or aluminium.

[0065] A method for inserting internal magnets 700 into a hollow shaft 600 using a device according to the disclosure is now described with reference to Figures 4A-E. In the following, the use of two magnets is described. However, it is to be understood that one or more may be used. Reference numerals have been maintained from previous figures throughout Figures 4A-E. In any example of the disclosure, alternatively or additionally, a device according to the disclosure may be used in a method of removing internal magnets from a hollow shaft.

[0066] In any example of the disclosure, a method for inserting internal magnets into a hollow shaft is provided in which a device according to any example of the disclosure is provided. A hollow shaft is then supported in the fixed member before inserting a plurality of internal magnets into the hollow shaft through an open end thereof such that each internal magnet experiences a repulsive force from its neighbour axially along the hollow shaft. Simultaneously or subsequently to inserting the internal magnets, the method includes inserting an insertable member into the open end of the hollow shaft and pushing the internal magnets into the hollow shaft with the insertable member. The method then includes positioning one of the first and second magnets axially and / or radially relative to the hollow shaft so as to attract the magnet closest to the open end of the hollow shaft, so as to maintain the plurality of internal magnets in position within the hollow shaft when the insertable member is removed. It will be understood that once the one of the first and second magnets has been positioned, the insertable member can be removed from the hollow shaft before inserting a further internal magnet into the hollow shaft.

[0067] In any example of the disclosure, simultaneously or subsequently to inserting the further internal magnet, the method may include again inserting the insertable member into the open end of the hollow shaft and pushing the internal magnets into the hollow shaft with the insertable member. The method may then continue repeating the steps set out above, first by includes positioning the other of the first and second magnets axially and / or radially relative to the hollow shaft so as to attract the magnet closest to the open end of the hollow shaft, so as to maintain the plurality of internal magnets in position within the hollow shaft when the insertable member is removed,

[0068] In any example of the disclosure, a method for removing internal magnets from a hollow shaft, is provided in which a device according to any example of the disclosure is provided. The method then includes supporting a hollow shaft in the fixed member. the hollow shaft comprises: a plurality of internal magnets arranged such that each internal magnet experiences a repulsive force from its neighbour in an axial direction along the hollow shaft; and a closing member configured to close an open end of the hollow shaft so as to retain the plurality of internal magnets therein. The method includes positioning one of the first and second magnets axially and / or radially relative to the hollow shaft so as to attract the closest to the open end of the hollow shaft, so as to maintain the plurality of internal magnets in position when the closing member is removed; removing the closing member; and moving the one of the first and second magnets out of position such that the repulsive force between each neighbouring internal magnet causes each internal magnet to move axially along and out of the hollow shaft.

[0069] In any example of the disclosure, the method may further include installing a removal member proximal the open end of the hollow shaft, for example after removing the closing member and / or before moving the one of the first and second magnets out of position.

[0070] In any example of the disclosure, wherein the removal member may be configured such that, when the first magnet is configured such that the repulsive force between each neighbouring internal magnet causes each internal magnet to move relative to its neighbour, the plurality of internal magnets remain axially aligned and come to rest within the hollow shaft and removal member.

[0071] Various steps in the above methods will now be described in further detail and according to various example of the disclosure. With reference to Fig. 4A, the hollow shaft 600 has been placed in the device 100, so as to be supported by the fixed member 200. In the present example, the removable cap 610 has been attached to the second axial end of the hollow shaft 600 so as to close that end of the hollow shaft. A plurality of internal magnets 700 is inserted into the hollow shaft 600 during the method. In the example shown, eight internal magnets 700 have so far been placed into the hollow shaft 600. Of course, more or less than eight internal magnets 700 may initially be inserted. It will be understood that the following method has been utilised to arrive at the arrangement shown in Fig. 4A. That is, the adding of further internal magnets is a repetitive process.

[0072] In the present example, the internal magnet 700 at the second axial end 604 of the hollow shaft 600 is smaller than the remaining magnets 700. This is to accommodate the cap 610. The plurality of internal magnets 700 are arranged in opposition. The plurality of internal magnets 700 may be axially stacked or arranged axially adjacent to each other and / or in axial alignment with each other. That is, each of the plurality of internal magnets 700 is repelled from each of its neighbours. For example, a first magnet of the plurality is inserted in the hollow shaft 600 with its north and south poles facing the first axial and second axial ends of the hollow shaft 600, respectively. The next of the plurality of internal magnets 700 is inserted with the opposite polarity. That is, the next of the plurality of internal magnets 700 is inserted such that its north and south poles face the second axial and first axial ends of the hollow shaft 600 respectively.

[0073] In the present example, the intermediate member 320 comprises a first magnet and a second magnet 330a, 330b, wherein the first and second magnets 330a, 330b are longitudinally offset from each other, such that the first magnet 330a is closer to the second axial end of the hollow shaft 600 than the second magnet 330b. As will be understood later, the first and second magnets 330a, 330b are arranged such that the polarity of the first and second magnets 330a, 330b are opposite. That is, the first and second magnets 330a 330b have their north and south poles, respectively, closest to the hollow shaft 600. It will be understood that the first and second magnets 330a, 330b may instead have their south and north poles, respectively, closest to the hollow shaft 600.

[0074] In the present example, the second magnet 330b is moved into place such that the internal magnet 700p proximate the first axial end of the hollow shaft 600 is attracted to the second magnet 330b. By moved, it is understood that this may involve adjusting the moveable member 300, intermediate member 320 and / or rod 340b into position. In examples with electromagnets, this may further involve switching the electromagnet on / off. In the present example, the first magnet 330a is positioned such that the top of the internal magnet proximate the first axial end 602 of the hollow shaft 600 is longitudinally offset from the first magnet 330a.

[0075] With reference to Fig. 4B, a next step in the insertion method is shown in which a further (ninth) internal magnet 700n has been inserted into the hollow shaft 600. This further internal magnet 700n is inserted in opposition with its nearest neighbour, as described above. The insertable member 400 is inserted into the hollow shaft 600 and an axial force applied thereto. The applied force may be applied manually, for example by a user, or additionally or alternatively by gravity due to the weight of the insertable member 400. By applying a force to the insertable member 400, the further magnet 700n is pushed further into the hollow shaft 600, so as to overcome the repulsive force from its nearest neighbour 700p, and so as to be attracted to the first magnet 330a, as shown in Fig 4B. The insertable member 400 may be held in position using any of the means described above. In the present example, one of the through-holes of the moveable member 300 is aligned with the through-hole (not shown) of the tubular member 220 and a pin received therethrough so as retain the insertable member 400 and plurality of internal magnets 700 therein. It will be appreciated that the spacing between consecutive through-holes of the insertable member 400 is selected so that the plurality of internal magnets 700 can be retained in the positions shown. In other examples, the insertable member 400 may be retained manually by a user.

[0076] Once the insertable member 400 is held in position, the second magnet 330b is configured so as to reduce the attractive force or no longer apply a force to the plurality of internal magnets 700. This may be achieved by moving the moveable member 300, the intermediate member 320 and / or the rods 340b so as to move the second magnet away from the hollow shaft 600. In the present example, the intermediate member 320 is pivoted away from the hollow shaft 600 (as shown in Fig. C). In examples where electromagnet is used, the electromagnet may be switched off.

[0077] With reference to Figs. 4C and D, the first magnet 330a is configured into place such that the further internal magnet 700n, now the internal magnet proximate the first axial end of the hollow shaft 600 is attracted to the first magnet 330a. As before, by configured, this may involve adjusting the moveable member 300, intermediate member 320 and / or rod 340a into position. It will be appreciated that the second magnet 330a is configured such that when the insertable member 400 is removed the plurality of internal magnets 700 are retained in place due to the attractive force of the first magnet 330a.

[0078] With reference to Figs. 4D and 4E, the insertable member 400 has been removed such that the first magnet 330a retains the plurality of internal magnets 700 within the hollow shaft 600 (see Fig. 4E). It will be appreciated than Figs. 4A-E show the steps for inserting a further internal magnet 700 in the hollow shaft 600, and therefore these steps can be repeated as many times as required to insert further internal magnets 700.

[0079] It will be appreciated that these steps can be repeated so as to completely fill the hollow shaft 600 with the desired number of internal magnets 700. Once filled with the desired number of internal magnets 700, the insertable member 400 may be removed from the hollow shaft 600 and the hollow shaft 600 may be closed by a closing member, for example a cap (not shown). It will be appreciated that this would not be achievable by only using the insertable member 400, for example.

[0080] It will be understood that in relation to the at least first and second magnets 330a, 330b, the at least first and second magnets 330a, 330b is in a use position when the at least first and second magnets 330a, 330b is positioned relative to the hollow shaft 600 so as to attract the magnet 700p closest to the open end of the hollow shaft 600.

[0081] Once the hollow shaft 600 has been sufficiently filled with the desired plurality of internal magnets 700 and closed, the filled hollow shaft 600 may be used as a rod in an actuator, for example, a linear actuator.

[0082] In any example of the disclosure, a method of assembling an actuator in which a plurality of internal magnets are inserted into a hollow shaft according to any example of the disclosure is provided. The open end of the hollow shaft is closed with a closing member so as to retain the plurality of internal magnets in the hollow shaft. The method then includes installing the closed hollow shaft in an actuator, such as a linear actuator for example. The method may further comprise linking a position sensor to the hollow shaft via the cap.

[0083] With reference to Fig. 5, a step in the removal of the plurality of internal magnets 700 is shown. As will be understood, a hollow shaft 600 completely filled with a plurality of internal magnets 700 can be placed in the device according to the disclosure, so as to be supported by the fixed member 200. In the present example, the hollow shaft 600 comprises a closing, for example, a cap (not shown), at the first axial end 602 that retains the plurality of internal magnets 700 therein. The first and / or second magnets 330a, 330b have been configured (not shown) such that when the cap (not shown) is removed, the plurality of internal magnets 700 are retained in place. It will be understood that the first and / or second magnets 330a, 330b are configured in similar manner as for the insertion steps outlined above. The cap is removed to make the plurality of internal magnets 700 accessible, and the plurality of internal magnets 700 are retained in place by the first and / or second magnets 330a, 330b. The plurality of magnets may then be removed by any known means. For example, by hand, by further magnets or otherwise.

[0084] The device may comprise a removal member to safely remove and protect the plurality of magnets 700 during the removal of the plurality of magnets 700. In the present example, a removal sleeve 800 has been placed at the first axial end of the hollow shaft 600. In use, the first and / or second magnets 330a, 330b can be configured such that the plurality of internal magnets 700 are repelled from each of their neighbours so as to translate axially along the hollow shaft 600, with some of the plurality of internal magnets 700 translating into the removal sleeve 800. By providing a removal member, such as the removal sleeve 800, the plurality of internal magnets 800 may freely repel each other in a controlled and contained manner for subsequent removal. It will be understood that without a removal member, the plurality of internal magnets 700 may be forced apart to such an extent as to exit the hollow shaft 700, and, for example, hit the floor. Therefore, the removal member allows the plurality of magnets 700 to reach their desired state in a controlled manner, leading to their safe removal from the hollow shaft 600.

[0085] In the present example, the removal sleeve 800 extends from the hollow shaft 600. In particular, the removal sleeve 800 is dimensioned so as to have the same radial cross-section shape and size as the hollow shaft 600. However, this is not essential and cross-sections may differ. It will be understood that the length of the removal member is sized suitably and is dependent on at least the number, mass and strength of the plurality of internal magnets 700, so as to provide safe removal. In other examples, the removal member need not be a sleeve. For example, the surface of the sleeve may comprise one or more holes so as to save material costs and still perform its function. In other examples, the removal member may comprise a series of elongate members extending axially away from the first axial end 602 of the hollow shaft 600 that contain the released plurality of internal magnets 700. In some examples, the removal member may comprise a closing member (not shown), for example a cap, so as to ensure the plurality of internal magnets 700 do not inadvertently exit the removal sleeve.

[0086] While the disclosure has been described in detail in connection with only a limited number of examples, it should be readily understood that the disclosure is not limited to such disclosed examples. Rather, the disclosure can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the scope of disclosure. Additionally, while various examples of the disclosure have been described, it is to be understood that aspects of the disclosure may include only some of the described examples. Accordingly the disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

1. A device for aiding in inserting internal magnets into a hollow shaft and / or removing internal magnets from the hollow shaft, the hollow shaft extending along a longitudinal axis, the device comprising: a fixed member configured to support the hollow shaft; a first magnet mounted such that, when in a use position, the north pole of the first magnet faces the hollow shaft; and a second magnet mounted such that, when in a use position, the south pole of the second magnet faces the hollow shaft, wherein the first and second magnets are axially moveable relative to the fixed member.

2. The device of claim 1, wherein at least one of the first and second magnets is able to move radially relative to the hollow shaft.

3. The device of claim 1 or 2, wherein the first and second magnets are configured to be external to the hollow shaft and configured to align with a respective internal magnet of a plurality of axially stacked internal magnets in the hollow shaft.

4. The device of any preceding claim, wherein the first and second magnets are axially offset from each other.

5. The device of any preceding claim, wherein the device comprises a moveable member, wherein the first and second magnets are mounted on the moveable member and the moveable member is axially moveable relative to the fixed member so as to move the first and second magnets axially.

6. The device of claim 5, wherein the moveable member comprises a rotating member, wherein the first and second magnets are mounted on the rotating member, wherein the rotating member is configured to rotate about the moveable member such that the first and second magnets are moveable radially relative to the longitudinal axis.

7. The device of any preceding claim, comprising an insertable member configured to be inserted into the hollow shaft along the longitudinal axis.

8. The device of any preceding claim, wherein at least one of the first and second magnets is a permanent magnet, and / or wherein at least one of the first and second magnets is an electromagnet.

9. The device of any preceding claim, wherein at least one the first and second magnets comprise a protective layer configured to protect the hollow shaft against damage caused by contact with the at least one of the first and second magnets.

10. The device of any preceding claim, wherein at least one of the first and second magnets is removeable from the moveable member.

11. A method for inserting internal magnets into a hollow shaft, the method comprising: providing the device of any preceding claim; supporting a hollow shaft in the fixed member; inserting a plurality of internal magnets into the hollow shaft through an open end thereof such that each internal magnet experiences a repulsive force from its neighbour axially along the hollow shaft; simultaneously or subsequently inserting an insertable member into the open end of the hollow shaft; pushing the internal magnets into the hollow shaft with the insertable member; and positioning one of the first and second magnets axially and / or radially relative to the hollow shaft so as to attract the magnet closest to the open end of the hollow shaft, so as to maintain the plurality of internal magnets in position within the hollow shaft when the insertable member is removed.

12. The method of claim 11, wherein the method further comprises: removing the insertable member from the hollow shaft; inserting a further internal magnet into the hollow shaft.

13. A method for removing internal magnets from a hollow shaft, the method comprising: providing the device of any of claims 1 to 10; supporting a hollow shaft in the fixed member, wherein the hollow shaft comprises: a plurality of internal magnets arranged such that each internal magnet experiences a repulsive force from its neighbour in an axial direction along the hollow shaft; and a closing member configured to close an open end of the hollow shaft so as to retain the plurality of internal magnets therein, the method further comprising: positioning one of the first and second magnets axially and / or radially relative to the hollow shaft so as to attract the internal magnet closest to the open end of the hollow shaft, so as to maintain the plurality of internal magnets in position when the closing member is removed; removing the closing member; and moving the one of the first and second magnets out of position such that the repulsive force between each neighbouring internal magnet causes each internal magnet to move axially along and out of the hollow shaft.

14. The method of claim 13, comprising installing a removal member proximal the open end of the hollow shaft, for example after removing the closing member and / or before moving the one of the first and second magnets out of position.

15. A method of assembling an actuator, the method comprising: inserting a plurality of internal magnets into a hollow shaft by the method of claim 11 or 12; closing the open end of the hollow shaft with a closing member so as to retain the plurality of internal magnets in the hollow shaft; and installing the closed hollow shaft in an actuator.

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