A support structure and a stator or rotor

Abstract

A support structure 10 for supporting a conductor and forming a stator or a rotor including first 10a and second 10b opposite ends; and a side wall 12 for receiving the conductor, wherein the side wall extends axially along an axis A between the first and second ends to define an internal space S. The side wall includes a surface which faces in a transverse direction with respect to the axis A; and the surface includes formations 20 for separating respective portions of a conductor of the stator or rotor along the side wall. The formations may extend from the first to the second end. The side wall may include openings for receiving respective portions of the conductor so that the portions of the conductor extend through the side wall. Formations may extend in a first direction on the outer surface and extend in a second direction on the inner surface which is transverse to the first direction, to form a zig-zag pattern with respect to the inner and outer surfaces. Projection members 14a, 14b, may be provided that are connected to and extend away from one or both of the first and second ends. The projection members may demarcate formations which separate the conductors.

Description

FIELD The present invention relates to electric machines, for example, electric motors and generators. More particularly, the present invention relates to a support structure for supporting a conductor and forming a stator or rotor. BACKGROUND Stators and rotors may be used in electric machines including, for example, electric motors and generators. An electric motor includes a rotor and stator. The rotor includes one or more magnets, and the stator includes electric conductors arranged around the stator, often in the form of windings. When electric current is passed through the electric conductors, the magnetic field from the magnets interacts with the electric current to exert a force on the rotor which causes the rotor to rotate. For certain types of electric motor, e.g. induction motors, the rotor may include electric conductors, e.g. windings, around it and the electric current supplied to the stator is an alternating phase current which causes current to be induced in the electric conductors on the rotor. This causes a magnetic field interaction between the rotor and stator so that the rotor rotates. A generator may have a similar arrangement of rotor and stator except the rotor is rotated by mechanical means and rotation of the rotor induces a current in the electrical conductor / conductors around the stator for use as electricity downstream of the generator. Prior art stators and rotors include electric conductors which are insulated to avoid short circuits caused by conductors being in contact. An issue that may arise is that the electric conductors on the stator / rotor may reach relatively high temperatures and become damaged during operation. Electric conductors may also become loose, deformed and / or displaced from the stator or rotor or relative to neighbouring conductors. This can cause the conductors to wear down and / or cause any insulative material around the conductors to be damaged in particular in this way. Prior art motors and generators may be controlled to limit aspects of their operation, e.g. by limiting the speed of rotation and / or the current, to address such issues. BRIEF DESCRIPTION OF THE INVENTION According to an aspect of the present invention we provide a support structure for supporting a conductor and forming a stator or a rotor including: first and second opposite ends; and a side wall for receiving the conductor, wherein: the side wall extends axially along an axis A between the first and second ends to define an internal space; the side wall includes a surface which generally faces in a transverse direction with respect to the axis A; and the surface includes formations for separating respective portions of a conductor of the stator or the rotor along the side wall. Optionally or preferably the formations extend from the first end to the second end. Optionally or preferably the side wall includes openings for receiving respective portions of the conductor so that the respective portions of the conductor extend through the side wall. According to another aspect of the present invention we provide a support structure for supporting a conductor and forming a stator or a rotor, the support structure including: first and second opposite ends; and a side wall for receiving the conductor, wherein: the side wall extends between the first and second ends to define an internal space; the side wall includes formations for separating respective portions of a conductor of the stator or the rotor along the side wall, and wherein the formations extend from the first end to the second end. According to another aspect of the present invention we provide a support structure for supporting a conductor and forming a stator or a rotor, the support structure including: a first and second opposite ends; and a side wall for receiving the conductor, wherein: the side wall extends between the first and second ends to define an internal space; the side wall includes formations for separating respective portions of a conductor of the stator or the rotor along the side wall, and wherein the side wall includes openings for receiving respective portions of the conductor so that the respective portions of the conductor extend through the side wall. Optionally or preferably the support structure according to any preceding aspect wherein the side wall includes: an inner surface which faces inwardly towards the internal space; and an outer surface which faces outwardly away from the internal space; wherein the inner and / or outer surfaces include the formations. Optionally or preferably the support structure according to any preceding aspect the formations include formations which extend in a first direction on the outer surface and extend in a second direction on the inner surface which is transverse to the first direction, optionally or preferably the formations form a zig-zag pattern with respect to the inner and outer surfaces. Optionally or preferably the support structure according to any preceding aspect including projection members, wherein the projection members are connected to and extend away from one or both of the first and second ends. Optionally or preferably the support structure according to any preceding aspect the projection members are connected to respective formations, optionally or preferably the projection members are connected to distal ends of the respective formations. Optionally or preferably the support structure according to any preceding aspect the projection members include a first set of projection members and a second set of projection members, wherein the first set of projection members extend further away from the first and / or second ends than the second set of projection members extend away from the first and / or second ends. Optionally or preferably the support structure according to any preceding aspect wherein the first set of projection members are spaced apart from each other at equal intervals along the side wall. Optionally or preferably the support structure according to any preceding aspect including channels between the formations for receiving respective portions of the conductor. Optionally or preferably the support structure according to any preceding aspect the formations define the channels in which respective portions of the conductor are received. Optionally or preferably the support structure according to any preceding aspect wherein the formations are ribs formed on or as part of the side wall. Optionally or preferably the support structure according to any preceding aspect wherein one or more of the formations are generally elongate and / or straight, and / or one or more of the channels are generally elongate and / or straight. Optionally or preferably the support structure according to any preceding aspect wherein one or more of the formations are, or include portions which are, arcuate, optionally or preferably S-shaped and / or one or more of the channels are, or include portions which are, arcuate, optionally or preferably S-shaped. Optionally or preferably the support structure according to any preceding aspect wherein at least a portion of the formations are connected to form at least one continuous path which extends along inner and outer surfaces of the side wall for the conductor to extend along the inner and outer surfaces of the side wall whilst keeping respective portions of the conductor separate from each other, optionally or preferably wherein the at least one continuous path encircles at least a portion of the space and optionally or preferably encircles all of the space. Optionally or preferably the support structure according to any preceding aspect wherein the at least one continuous path forms a generally helical path around the side wall which traverses the inner and outer surfaces alternately. Optionally or preferably the support structure according to any preceding aspect wherein the at least one continuous path alternates between inner and outer surfaces of the side wall, optionally or preferably the at least one continuous path: extends in a first direction as the at least one continuous path extends along the outer surface from a first point near to, or on the first end to a second point near to or on the second end, and extends in a second direction, which is transverse to the first direction, as the at least one continuous path extends along the inner surface from the second point to a third point near to, or on the first end. Optionally or preferably the support structure according to any preceding aspect wherein the channels are connected to form a lengthened channel which follows the at least one continuous path. A stator or rotor including a support structure according to any preceding aspect and including the conductor. Optionally or preferably the support structure according to any preceding aspect including a plurality of conductors and wherein the formations separate respective ones of the plurality of conductors from each other. Optionally or preferably the support structure according to any preceding aspect each of the plurality of conductors follows a separate section of the at least one continuous path to complete at least one revolution around the side wall, or wherein the formations are connected to form a plurality of said continuous paths for the plurality of conductors, wherein respective ones of the plurality of said continuous paths are separate paths for respective ones of the plurality of conductors and the formations keep the plurality of conductors separated from each other. A stator or rotor optionally or preferably including a support structure according to any preceding aspect wherein the projection members demarcate formations which separate the conductor or respective ones of the plurality of conductors. A stator or rotor optionally or preferably including a support structure according to any preceding aspect wherein the first set of projection members demarcate respective ones of the plurality of said continuous paths. A stator or rotor optionally or preferably including a support structure according to any preceding claim wherein the support structure is connected to a mounting member to form a stator or rotor. A stator or rotor according to any preceding aspect wherein the support structure and mounting member are bonded together to form the rotor or stator, optionally or preferably the support structure and mounting member are made from the same material. A support structure or stator / rotor according to any preceding aspect wherein the formations include one or more retaining members which define respective openings between the formations for receiving respective portions of the conductor. A support structure or stator / rotor according to any preceding aspect wherein the conductor(s) are made from carbon nanotube yarn. A stator / rotor according to any preceding aspect wherein an insulative material covers the conductor(s) and the support structure to form a substantially sealed structure. A support structure or stator / rotor according to any preceding aspect wherein the conductor(s) do not have an insulative coating and / or the formations provide an insulative barrier between, or electrically isolate, the respective portions of the conductor or the plurality of conductors. A support structure according to any preceding aspect wherein the support structure is generally annular shaped, and optionally or preferably cylindrical. A support structure according to any preceding aspect wherein the support structure is manufactured using an additive manufacturing method. According to another aspect of the present invention we provide an electric motor or generator including a stator formed from a support structure of any one of the preceding aspects and a rotor, optionally or preferably the motor or generator has the stator and rotor arranged in an axial flux or raxial flux arrangement. BRIEF DESCRIPTION OF THE FIGURES In orderthatthe present disclosure may be more readily understood, preferable embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a perspective view of an example of a support structure embodying the present disclosure; FIGURE 2 is a perspective view showing a portion of the support structure of figure 1; FIGURE 3 is a perspective view showing another portion of the support structure of figure 1 with a conductor supported thereon; FIGURE 4 is a perspective view of the support structure of figure 1 within a plurality of conductors supported thereon; FIGURE 5 is a perspective view showing a portion of the support structure as shown in figure 4; FIGURE 6 is a perspective view showing the support structure of figure 4 partially transparent with a single conductor supported thereon; FIGURE 7a is a perspective view showing a portion of the support structure of figure 6; FIGURE 7b is a perspective view showing the portion of the support structure of figure 7a partially transparent; FIGURE 8a is a plan cross-section view through a centre line of the support structure as shown in figure 6; FIGURE 8b is a plan cross-section view through a centre line of a support structure according to another example embodying the present disclosure; FIGURE 9 is a perspective view of a stator including the support structure of figure 1 supporting a plurality of conductors embodying the present disclosure; FIGURE 10 is a perspective view showing a rotor and stator assembly including the stator of figure 9 embodying the present disclosure with a portion removed; FIGURE 11 is a side view of the rotor and stator assembly of figure 10 with a portion removed; FIGURE 12 is a plan view of the rotor and stator assembly of figure 10 with a portion removed; FIGURE 13 is a side view showing another example of a support structure embodying the present disclosure; FIGURE 14 is a side view showing another example of a support structure embodying the present disclosure; FIGURE 15 is a perspective view showing a portion of another example of a support structure embodying the present disclosure; and FIGURE 16 is a schematic cross-section view showing a portion of another example of a support structure embodying the present disclosure. DETAILED DESCRIPTION OF THE DISCLOSURE Referring to figure 1, this is a perspective view of a support structure 10 for supporting a conductor (not shown) and forming a stator or rotor according to an aspect of the present disclosure. The support structure 10 has first and second opposite ends 10a, 10b, and a side wall 12 for receiving the conductor which extends between the first and second ends 10a, 10b to define an internal space S. The side wall 12 includes formations 20 for separating respective portions of the conductor along the side wall 12. The formations 20 extend from the first end to the second end 10a, 10b. The formations 20 may also retain the respective portions of the conductor in place relative to the side wall 12. The support structure 10 may be configured as a bobbin which is a term of the art of electric motors and generators. The support structure 10 may be annular shaped. In this example, the support structure 10 is generally cylindrical and extends axially along an axis A. The first and second ends 10a, 10b are at the respective end / open faces of the support structure 10. The first and second ends 10a, 10b define respective edges of the support structure 10 in this example. The support structure 10 may be formed as a rigid structure. In examples, the support structure 10 may be formed from an electrically conductive material. In other examples, the support structure 10 may be formed from an electrically insulative material. For example, a ceramic or polymer material.. Suitable materials include aluminium nitride, boron nitride or Polyether Ether Ketone (PEEK). The support structure 10 may be formed as an insulative structure, e.g. formed from an insulative material, which does not conduct electricity. The side wall 12 may include an inner surface 12a which faces inwardly towards the internal space S, e.g. radially towards the internal space S, and an outer surface 12b which faces outwardly away from the internal space S, e.g. radially away from the internal space S. The formations 20 may be integrally formed as part of the side wall 12. One or both of the inner and outer surfaces 12a, 12b may include the formations 20. In the example shown in figures 1 to 3, both surfaces 12a, 12b include the formations 20. In examples, the support structure 10 may be formed as a single integrally formed component piece, and in other examples the structure 10 may be formed from multiple parts which are connected together. In examples, the support structure 10 may be made using an additive manufacturing technique. In examples, the support structure 10 may be made from other manufacturing techniques which may include forming or subtractive manufacturing processes. In examples, the support structure 10 may be formed from a ceramic tube by laser etching the ceramic tube. This may provide benefits such as lower cost, improved accuracy and have a reduced time of production. The formations 20 may be raised sections or ribs formed on or as part of the side wall 12. The formations 20 may be generally elongate and / or straight as shown in figures 1 and 2. In other examples, the formations 20 may be arcuate or include arcuate portions. Referring to figure 13, this shows the support structure 10 having formations 20 which include arcuate portions, the formations 20 may be generally S-shaped as shown in the example support structure 10 shown in figure 14. For the example shown in figures 1 and 2, the formations 20 are inclined with respect to the vertical at around 45 degrees but may be inclined at other angles in examples. The formations 20 are inclined so that the conductor may be retained onto the side wall 12 as a coil. In this example, the formations 20 include formations which extend in a first direction on the outer surface 12b, e.g. parallel with each other, and extend in a second direction on the inner surface 12a, e.g. parallel with each other, which is transverse to the first direction. The formations 20 form a zig-zag like pattern with respect to the inner and outer surfaces 12a, 12b. In the example shown in figures 1 and 2, the formations 20 on the outer surface 12b are inclined at around 45 degrees with respect to the formations 20 on the inner surface 12a but may be inclined at different angles with respect to each other in other examples. Referring to figure 2, which is an enlarged perspective view of a portion of the support structure 10, the support structure 10 may include channels 22 between the formations 20 for receiving respective portions of the conductor. In this example, the formations 20 define the channels 22, e.g. pairs of adjacent formations 20 define respective channels 22. It can be seen that adjacent formations 20a, 20b, define a channel 22a. The channels 22 may be formed to be generally elongate and straight. The channels 22 may extend from the first end 10a to the second end 10b. For example, the channels 22 may be arranged as shown in figures 1 and 2 so that the channels 22 on the inner and outer surfaces 12a, 12b are connected with their respective distal ends being connected about the first and second ends 10a, 10b. The channels 22 may be recesses which are u-shaped in crosssection. In other examples, the channels 22 may be shaped differently, e.g. they may be arcuate or S-shaped (see figures 13 and 14 for respective examples of arcuate and s-shaped channels). In the example shown in figure 2, the channels 22 are inclined and form a zig-zag pattern in the same sense as the formations 20 because the channels 22 are defined by the formations 20. In other examples, the channels 22 may not be defined by the formations 20, e.g. they could be formed as separate recesses in the side wall 12 and the formations 20 may simply separate the recesses so that the portions of the conductor are not in contact. In such examples, the channels 22 may still be shaped, orientated and / or arranged in the spatial and geometric configurations described previously for which they are defined by the formations 20 without departing from the scope of the present disclosure. The formations 20 may effectively define channels 22 which are shaped as slots or grooves which receive respective portions of the conductor whilst keeping the portions separate from each other so that they are not in contact. Respective ones of the channels 22 defined by the formations 20 may be connected or in communication with each other to define one or paths or sections that the conductor may follow. The support structure 10 may include projection members 14 which are connected to and extend away from one or both of the respective ends 10a, 10b. Referring to figures 2 and 3 in particular, in the example shown the support structure 10 includes projection members 14 on both ends 10a, 10b. For example, ones of the projection members 14 may be connected to the formations 20, e.g. connected to first distal ends 19’ thereof, and other ones of the projection members 14 may be connected to the formations 20 at second, opposite, distal ends 19” thereof. The projection members 14 may be integrally formed as part of the formations 20 in examples or may be separate component parts connected thereto. The projection members 14 extend generally axially to form a series of tabs or teeth-like formations spaced around the ends 10a, 10b. The projection members 14 may have different shapes or profiles so that the parts of the channels 22 defined by them have a different profile compared to the rest of the channels 22. The projection members 14 provided at one or both of the ends 10a, 10b may include a first set of projection members 14a and a second set of projection members 14b. For the example shown in figures 1 and 2, only the first end 10a has first and second sets of projection members 14a, 14b. The first set of projection members 14a may extend further away from the first end 10a than the second set of projection members 14b extend away from the first end 10a. The projection members 14a are longer or extend further proud of the rest of the first end 10a than the projection members 14b. The first set of projection members 14a may be spaced apart from each other at equal intervals along the side wall. The first set of projection members 14a may divide the second set of projection members 14b into groups such that there are a given number of projections 14b, and channels 22 between adjacent projection members 14a. In this example, there are an equal number, two projection members 14b and three channels 22, between adjacent projection members 14a. In examples, the projection members 14a may divide the projection members 14b and channels 20 differently, e.g. in greater or fewer numbers and / or unequal numbers between adjacent projection members 14a. The projection members 14 guide the conductor over the edges at the first and second ends 10a, 10b whilst keeping the respective portions of the conductor separate and electrically isolated from each other. The formations 20 may be arranged to form one or more paths which extend around the side wall 12 and to encircle or circumscribe the space S. Respective ones of the channels 22 may be connected or in communication with each other to form one or more lengthened channels. With reference to figure 3, this shows the support structure 10 of figures 1 and 2 with a conductor 34 provided thereon and is an enlarged view of a portion of the support structure 10. In the example shown in figures 1 to 3, the formations 20 form six separate continuous paths which extend along the inner and outer surfaces 12a, 12b of the side wall 12 for six respective conductors to extend along the inner and outer surfaces 12a, 12b of the side wall 12 whilst keeping respective portions of the conductors separate from each other. In figure 3, a single conductor 34 is shown extending along one of the continuous paths. In this example, the channels 22 are connected to form six separate single lengthened channels and respective ones of the lengthened channels correspond to one of the six continuous path defined by the formations 20 as will be described. Figure 4 is a perspective view of the support structure 10 of figures 1 to 3 having six separate conductors 30a, 30b, 32a, 32b, 34a, 34b thereon and figure 5 is an enlarged view showing a portion of the said support structure 10 in perspective view. Conductors 30a, 30b are denoted by a first colour, conductors 32a, 32b are denoted by a second colour, and conductors 34a, 34b are denoted by a third colour. The formations 20 are connected to form six separate single continuous paths 40a, 40b, 42a, 42b, 44a, 44b. With reference to figure 6, this shows the support structure 10 of figures 1 to 3 with only conductor 30a placed thereon extending along the continuous path 40a. The path is a generally helical pattern around the side wall 12 which traverses the inner and outer surfaces 12a, 12b. The support structure 10 may include a locating portion 60 for locating the conductors 30a, 30b, 32a, 32b, 34a, 34b, with respect to the continuous paths 40a, 40b, 42a, 42b, 44a, 44b. The locating portion 60 may be provided on side 10a. The locating portion 60 has six parts 60a, 60b, 60c, 60d, 60e, 60f which are positioned adjacent to each other. Part 60a is shown in figures 7a and 7b. Part 60a locates two sets of three adjacent channels across respective surfaces 12b, 12a. Referring to figure 7a, part 60a locates three channels 22a, 22b, 22c on the surface 12b that are defined by four adjacent formations 20a, 20b, 20c, 20d. Part 60a has a first locating formation 60’a which defines the starting point of the continuous path 40a and from where conductor 30a starts on the continuous path 40a. The first locating formation 60’a forms a closed distal edge of channel 22a on surface 12b at the side 10a and a closed distal edge of the channel 22a” on surface 12a which would otherwise be connected or adjoined to the channel 22a on the surface 12b. Part 60a has shaped edges at the distal ends of the three immediately adjacent formations 20b, 20c, 20d on surface 12b so that the two channels 22b, 22c defined by the adjacent formations 20b, 20c, 20d are open and connected or adjoined to the channels 22a’, 22b’, 22c’ on the opposite surface 12a. Corresponding ones of the first locating formation 60’a and shaped edges of part 60a on surface 12b are similarly formed on the corresponding formations 20a’, 20b’, 20c’, 20d’ on surface 12a except that the first locating formation 60’a is positioned at the opposite end of the part 60a compared to the first locating formation 60’a on the surface 12b. The first locating formation 60’a on the surface 12b is for locating where the conductor 30a leaves the support structure 10 as will be described. The adjacent parts 60b, 60c, 60d, 60e, 60f are formed in the same way with the first locating formation 60’b of the second part 60b shown in figures 7a and 7b. The continuous path 40a alternates between opposite surfaces 12a, 12b as it extends around the side wall 12 to complete three full revolutions. The conductor 30a may be placed or wound onto the support structure 10 along the continuous path 40a. The conductor 30a is a single piece having opposite ends 30’a, 30”a. A first end 30’a is positioned adjacent the first end 10a and a portion of the conductor 30a at the first end 30’a is placed onto a point 50a of the continuous path 40a on the first end 10a at the locating formation 60’a of the part 60a. In examples, this portion of the conductor 30a may be connected to the side wall 12 to fix the portion in place. In examples, a mechanical fixing, e.g. a clip or fastening, may be used to fix the portion in place. In examples, adhesive may be applied to the conductor 30a to bond the portion of the conductor 30a to the channel 22 at this point. A resin which is cured, e.g. by a UV curing process, may be used in examples. The point 50a is a distal end of the channel 22a defined between the formations 20a, 20b at the first end 10a. From here, the conductor 30a is placed or wound along the continuous path 40a to follow the path 40a which alternates between the inner and outer surfaces 12a, 12b of the side wall 12 until its second end 30”a reaches the first end 10a at a point near the point 50a to extend freely away from the support structure 10 as shown in figure 6. A portion of the conductor 30a at the second end 30”a may be connected to the side wall 12 to fix the portion in place similar to the portion at the first end 30’a at the other first locating formation 60’a of the first part 60a. The conductor 30a extends around the side wall 12 following continuous path 40a and is received within the respective channels 22 that are connected together along the path 40a. Referring to figure 8a, this is a plan cross-section across a portion of the side wall 12 in plan view showing the conductor 30a in place. It can be seen that the formations 20 separate portions of the conductor 30a which are adjacently spaced to each other along the side wall 12 from each other. The formations 20 act as walls which sit between the portions of the conductor 30a to prevent any contact between the said portions. In the example shown in figure 8a, the formations 20 are raised with respect to the rest of the surfaces 12a, 12b and have a height h which is around half the diameter of the conductor 30a. The height h may be defined with respect to the lowest point of the channels 22 defined by the formations 20. In other examples, the formations 20 may be raised a different height h. For example, as shown in figure 8b, the formations 20 may have a height h which is around the same as the diameter of the conductor 30a. In more detail, the path 40a starts at the first locating formation 60’ at point 50a from which it extends in a first direction, which is inclined relative to the vertical, along the outer surface 12b to a point 50b on the second end 10b as shown in figure 6. From here, path 40a then extends in a second direction, which is inclined and transverse to the first direction, along the inner surface 12a to a point 50c on the first end 10a. The point 50c is circumferentially spaced apart from the point 50a along the first end 10a. The path 40a continues this pattern to follow a generally helical path until it completes a revolution of the side wall 12 and then reaches a point 52a adjacent to point 50a. From point 50a, the path 40a follows a similar pattern as the first revolution to complete a second revolution of the side wall 12. The path 40a then continues from a point 54a adjacent 52a following a similar pattern again to complete a third revolution of the side wall 12. The other paths 40b, 40c, 40d, 40e, 40f are similarly formed to extend around the side wall 12 and the paths 40a to 40f cover all of the inner and outer surfaces 12a, 12b of the side wall 12. The conductor 30a follows the path 40a along the described path until the second end 30”a returns to a point on the inner surface 12a of the side wall 12 defined by the other locating formation 60’a and extends freely away or sits loose from the support structure 10 as shown in figure 6. The conductors 30b, 32a, 32b, 34a, 34b follow respective paths 40b, 42a, 42b, 44a, 44b of the path in a similar way to the way in which conductor 30a follows path 40a. The conductors 30b, 32a, 32b, 34a, 34b, start and terminate at the respective parts of the locating portion 60. Paths 40b, 42a, 42b, 44a, 44b are similar to path 40a and the paths are circumferentially spaced apart or offset with respect to each other. Each path 40a, 40b, 42a, 42b, 44a, 44b completes three revolutions around the inner and outer surfaces 12a, 12b ofthe side wall 12. The formations 20 separate the conductors 40a, 40b, 42a, 42b, 44a, 44b from each other as they follow their respective paths in the same way as that shown in figure 6 with respect to the single conductor 30a. Referring to figures 4 and 5, the conductors 30a, 30b have a first electrical phase, the conductors 32a, 32b, have a second electrical phase and conductors 34a, 34b have a third electrical phase. Conductors 30a, 30b are arranged along paths 40a, 40b such that respective portions of the conductor 30a extend along three adjacent channels 22 at a first position on the outer surface 12b ofthe side wall 12, and respective portions of conductor 30b extend along three adjacent channels 22 at a second position of the side wall 12 which is circumferentially spaced apart from the first position. The other conductors are arranged in a similar way and are positioned in the spaces between adjacent said first and second positions of the conductors 30a, 30b. In this way, respective groups of conductors having the same phase are positioned sequentially around the side wall 12 so that the first electrical phase is followed by the second electrical phase which is followed by the third electrical phase in a cyclical pattern around the side wall 12. The first set of projection members 14a may demarcate respective ones of the continuous paths 40a, 40b, 42a, 42b, 44a, 44b followed by the conductors, which may, for example, be based on the phase of the conductors. For example, projection members 14a’, 14a’ demarcate path 40a which receives the conductor 30a. For the projection members 14a’ denoted in figure 4, four formations 20 receive the conductor 30a within the three respective channels 22 defined by them and which are positioned between the adjacent pair of projection members 14a’. The conductors 30a, 30b, 32a, 32b, 34a, 34b may be manually placed onto the support structure 10 to follow their respective paths 40a, 40b, 42a, 42b, 44a, 44b in the manner described or by an automated process which performs this task. Once the conductors 30a, 30b, 32a, 32b, 34a, 34b have been placed on the support structure 10, an insulation coating may be applied to insulate the structure. For example, the structure may be overmoulded in an insulative material or potted in a manner known in the art. In examples, the separate continuous paths may complete more or fewer revolutions around the side wall 12 depending on the particular requirement of the support structure and / or conductors being supported therein for a particular application. In examples, rather than having separate continuous paths, the formations 20 may define a single continuous path which extends around the side wall 12 and the respective conductors may extend along respective separate sections of the single continuous path rather than having separate continuous paths for each conductor. In examples there may be three separate continuous paths, with each continuous path having two sections for two respective conductors. Similarly, the paths or sections may encircle only a portion of the space rather than the whole space. In examples, the support structure 10 may not have a locating portion 60 which locates the starting and terminating ends of the conductors onto the support structure 10 irrespective of whether there is a single continuous path with separate sections for the conductors, or multiple continuous paths for the conductors. The example shown in figures 4 and 5 has three pairs of conductors for a three phase electric machine with each pair being a different one of the three phases. In examples, the support structure 10 may support a different number of conductors and / or phases. The formations 20 may be arranged so that the conductors are supported on separate sections of the same path, or on separate paths in a similar manner to that previously described. For example, there may be six conductors supported by the support structure 10 and each conductor may be a different phase for a six-phase electric machine. The formations 20 may be arranged to define a single continuous path and the six conductors follow six respective sections of the path. Alternatively, the formations 20 may be arranged to define six separate continuous paths with each path having a respective conductor. Alternatively, the formations 20 may be arranged to define three separate continuous paths with each path having two sections so that each path has two respective conductors. Referring to figure 9, this is a perspective view of the support structure 10 shown in figure 4 assembled into a stator 100 with the conductors 30a, 30b, 32a, 32b, 34a, 34b installed onto the support structure 10. The stator 100 includes a mounting member 110 in the form of an annular disc with an inner ring 112 which extends upwardly and centrally from a surface of the mounting member 110 on which the stator 100 is mounted. The mounting member 110 has an annular wall 113 which extends around the peripheral part of the mounting member 110. The wall 112 does not extend all the way around the mounting member 110 and there is an open section or gap 114 between the open ends of the wall 113. A peripheral annular groove or recess 116 is defined on the surface of the mounting member 100 in which the support structure 10 is received. The support structure 10 (with conductors already placed thereon) is connected to the mounting member 110 by positioning the support structure 10 relative to the member 110 so that the first end 10a faces the mounting member 110 and the free ends of the conductors 30a, 30b, 32a, 32b, 34a, 34b are positioned at the gap 114. The support structure 10 is then placed into the recess 116 and fixed in place relative to the mounting member 110 to form the stator 100. Different ways of fixing the support structure 10 to the mounting member 110 may be used. According to one example, the support structure 10 and mounting member 110 are made from different or the same ceramic or other suitable non-electrically conductive materials and the components are bonded together. For example, an adhesive resin may be used to bond the support structure 10 to the mounting member 110 about the recess 116 and cured using a UV curing process. In other examples, the support structure 10 and mounting member 110 may be connected by mechanical means, e.g. by suitable fastenings. In examples, the support structure 10 and mounting member 110 may be made as a single integral component part rather than separate parts connected together. In such examples, the mounting member 110 may be modified as necessary to allow the conductors to be placed onto the support structure 10. Referring to figure 10, this is a perspective view of a rotor and stator assembly 200 with part of the assembly 200 shown in cross-section. The assembly 200 includes the stator 100 shown in figure 9 connected to a rotor 210. The rotor 210 has an annular main section 212 and a central shaft 214 connected to the main section 212. The main section 212 is in the form of a ring. Radially extending arms 218 connect the ring 216 to the shaft 214. The main section 212 includes a pair of concentric annular walls which define an internal space between them which is ring shaped and in which a plurality of magnets 219 are supported. The magnets 219 are arranged as concentric rings with a passage 220 between them in which the support structure 10 of the stator 100 is received. The magnets may be made from magnetic materials including one or more of Ferrite, Neodymium, Samarium Cobalt, or certain variants of Iron Nitride known in the art. An electric machine, e.g. a motor or generator, may include a rotor and stator assembly including a stator or rotor with a support structure embodying the present disclosure for which the rotor and stator arranged in different topologies known in the art. For example, the rotor and stator may be arranged in axial flux or raxial flux. The magnets 219 are arranged as a surface mounted magnet array in this example with respect to the stator 100. However, in examples, other arrangements of magnet may be adopted as is known in the art by the skilled person. For example, magnets arranged as interior permanent magnets or as a Halbach array . In other examples, the rotor 210 may have alternative torque armatures configurations which or may not utilise magnets. For examples, the rotor 210 may have conductors or windings arranged as synchronous reluctance, induction or wound field synchronous machines (WFSM) for alternative torque armatures. Bearings 222 are positioned in the inner ring 112 of the stator 100 and define a central opening through which the shaft 214 extends. The bearings 222 provide a rotational connection between the rotor 210 and the stator 100. The described features can variously be seen in figure 11 which is a side view of the stator 100 with a part removed to show the bearings 222 without the rotor 210, and figure 12 which is a plan view of the assembly 200 with a portion of the rotor 210 not shown. The assembly 200 may form part of an electric machine, e.g. electric motor or generator, and the free ends of the conductors connected to the electric / power circuits of the electric machine as will be understood by the skilled person. Although a particular type of assembly 200 has been described, it should be appreciated that the support structure 10 may be used for other types of assembly having different configurations and / or geometry without departing from the present disclosure. The formations 20 provide an advantage, in examples, of retaining the conductors in position along the main surfaces, i.e. surfaces 12a, 12b ofthe support structure 10 thus preventing them from being displaced from their original positions due to forces experienced during use ofthe electric machine. This may permit the electric machine to be used at higher speeds or loads due to the improved retention ofthe conductors regardless of whether the support structure is made from an electrically insulative material or not. An advantage ofthe support structure 10 when made from an electrically insulative material is that a conductor or conductors, e.g. conductors 30a, 30b, 32a, 32b, 34a, 34b, may be used with the structure 10 which have no insulative coating because the formations 20 separate the respective portions of the conductors) so that they are not in contact and / or electrically isolate them. The formations 20 may thus form an insulative barrier between the conductors and their respective portions in such examples. In examples, the conductor(s) having no insulative coating may be made from more widely used electrically conductive materials, e.g. copper and aluminium, or non-standard electrically conductive materials, e.g. carbon nanotubes (particularly carbon nanotubes in the form of carbon nanotube yarn), silver, or any other electrically conductive materials. As no insulative coating for the conductors is required in examples, the electric machine, e.g. motor or generator, incorporating such a support structure and conductors can be operated at higher temperatures without adversely affecting the conductors. For example, if the support structure and / or the conductors is made from materials having a relatively high melting point, e.g. a support structure made from a suitable ceramic material or a conductor made from carbon nanotubes, an electric motor may be operated at temperatures of 500°C or higher which is much higher than typical electric motors which must not exceed 200°C during operation. For examples where conductors having insulative coatings are provided on the support structure 10 and the support structure 10 is made from an electrically insulative material, then electric machines incorporating such support structures may be operated at higher speeds, loads, or temperature because even if the insulative coating were to fail, the formations 20 prevent the conductors from coming into electrical contact with each other. Where the support structure 10 is made from non-metal materials, e.g. ceramic materials, a substantial reduction in the metal content of an electric motor or generator using such a support structure 10 may be achieved. The examples described have formations 20 which extend from the first end 10a to the second end 10b of the side wall 12. In examples, the formations 20 may extend along only a portion of the side wall 12 rather than the whole length of the wall 12. In examples, the side wall 12 may include openings, e.g. apertures, for receiving respective portions of the conductor or conductors so that the conductors extend through the side wall rather than extending over the edges at ends 10a, 10b of the side wall 12. An example of such a support structure 10 having a single conductor 30a supported thereon is shown in figure 15 in partial view showing openings 70 at end 10a. In this example, the openings 70 are provided in respective first and second lines around the side wall 12. The first line of openings is near the end 10a, and the second line of openings is near the end 10b. In this example, the openings 70 are provided at distal ends of the side wall 12 at ends 10a and 10b but may be provided at only one of the ends and / or be provided at different relative positions on the side wall 12 in other examples. The projections 14 may be configured in a similar way to the previous examples except that the projections 14a form integral parts of the side wall 12 which are connected at their distal ends to the annular shaped ends 10a, 10b. The projections 14a and the ends 10a, 10b connected thereto define the openings 70 in this example. In this example, the conductors extend through the openings 70 following the channels 22 defined by the formations 20. The projections 14a aid in guiding the conductors through the openings 70 whilst keeping respective portions of the conductors separate to avoid contact between them. In this example, the support structure 10 is otherwise similar to the previous examples except that the annular shaped ends 10a, 10b connect to the projections 14a so as to define the openings between adjacent projections 14b. The conductors pass into and out of the openings 70 to follow respective paths around the side wall 12 in a manner similar to that described for the previous examples. With reference to figure 16, in examples the formations 20 include retaining members 21 which define respective openings 21 ’ between the formations 20 for receiving respective portions of the conductor. Figure 16 is a partial cross-section schematic view showing adjacent formations 20’, 20”. The retaining members 21 may extend towards each other from pairs of adjacent formations 20, such as the pair of formations 20’, 20” to define the openings 21’. The openings 21’ are in communication with the channels 22 and are smaller in width than the channels 22. The openings 21’ may extend along the length of the channels 22. The openings 21 ’ have a width that is smaller than the width or diameter of the conductor. Due to the conductors being made of materials which are at least partially elastic, particularly where the material is formed as bundle of relatively thinner strands, e.g. bundles of carbon nanotube yarns, the conductors can be pushed through openings 21’ causing them to be compressed and be positioned within the channels 22. The conductors then expand after passing through the openings 21 ’. In this way, the retaining members 21 retain the conductors in place within the channels and prevent them from becoming loose and / or moving out of the channels 22. In examples, the retaining members 21 are arranged to so that the conductors are compressed by the retaining members 21 when the conductors are positioned in the channels 22. The retaining members 21 effectively hold the conductors 22 in place in such arrangements. In the example shown in figure 16, the retaining members 21 may extend downwards into the channels 22 so that the height within the channels 22 for the conductors to fit into is reduced causing the conductors to push against the retaining members 22 when they are in the channels 22. In this example, the retaining members 21 curve downwardly to extend partially into the channels 22 as they extend towards each other from the adjacent formations 20’, 20”. The retaining members 21 are formed integrally with the formations 20 from the same material in this example but may be separate components which are connected to the formations 20 in other examples. When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components. The invention may also broadly consist in the parts, elements, steps, examples and / or features referred to or indicated in the specification individually or collectively in any and all combinations of two or more said parts, elements, steps, examples and / or features. In particular, one or more features in any of the embodiments described herein may be combined with one or more features from any other embodiment(s) described herein. Protection may be sought for any features disclosed in any one or more published documents referenced herein in combination with the present disclosure. Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and / or to encompass equivalents.

Claims

1. A support structure for supporting a conductor and forming a stator or a rotor including: first and second opposite ends; anda side wall for receiving the conductor, wherein:the side wall extends axially along an axis A between the first and second ends to define an internal space;the side wall includes a surface which generally faces in a transverse direction with respect to the axis A; andthe surface includes formations for separating respective portions of a conductor of the stator or the rotor along the side wall.

2. A support structure according to claim 1 wherein the formations extend from the first end to the second end.

3. A support structure according to claim 1 or 2 wherein the side wall includes openings for receiving respective portions of the conductor so that the respective portions of the conductor extend through the side wall.

4. A support structure for supporting a conductor and forming a stator or a rotor, the support structure including:first and second opposite ends; anda side wall for receiving the conductor, wherein:the side wall extends between the first and second ends to define an internalspace;the side wall includes formations for separating respective portions of a conductor of the stator or the rotor along the side wall, andwherein the formations extend from the first end to the second end.

5. A support structure for supporting a conductor and forming a stator or a rotor, the support structure including:a first and second opposite ends; anda side wall for receiving the conductor, wherein:the side wall extends between the first and second ends to define an internalspace;the side wall includes formations for separating respective portions of a conductor of the stator or the rotor along the side wall, andwherein the side wall includes openings for receiving respective portions of the conductor so that the respective portions of the conductor extend through the side wall.

6. A support structure according to any preceding claim, wherein the side wall includes:an inner surface which faces inwardly towards the internal space; and an outer surface which faces outwardly away from the internal space; wherein the inner and / or outer surfaces include the formations.

7. A support structure according to claim 6, wherein the formations include formations whichextend in a first direction on the outer surface and extend in a second direction on the inner surface which is transverse to the first direction, optionally or preferably the formations form a zig-zag pattern with respect to the inner and outer surfaces.

8. A support structure according to any preceding claim including projection members, wherein the projection members are connected to and extend away from one or both of the first and second ends.

9. A support structure according to claim 8 wherein the projection members are connected to respective formations, optionally or preferably the projection members are connected to distal ends of the respective formations.

10. A support structure according to claim 8 or 9, wherein the projection members include a first set of projection members and a second set of projection members, wherein the first set of projection members extend further away from the first and / or second ends than the second set of projection members extend away from the first and / or second ends.

11. A support structure according to claim 10 wherein the first set of projection members are spaced apart from each other at equal intervals along the side wall.

12. A support structure according to any preceding claim including channels between the formations for receiving respective portions of the conductor.

13. A support structure according to claim 12 wherein the formations define the channels in which respective portions of the conductor are received.

14. A support structure according to any preceding claim including one or more of all of: a) wherein the formations are ribs formed on or as part of the side wall.b) wherein one or more of the formations are generally elongate and / or straight, and / or one or more of the channels are generally elongate and / or straight.c) wherein one or more of the formations are, or include portions which are, arcuate, optionally or preferably S-shaped and / or one or more of the channels are, or include portions which are, arcuate, optionally or preferably S-shaped.d) wherein at least a portion of the formations are connected to form at least one continuous path which extends along inner and outer surfaces of the side wall for the conductor to extend along the inner and outer surfaces of the side wall whilst keeping respectiveportions of the conductor separate from each other, optionally or preferably wherein the at least one continuous path encircles at least a portion of the space and optionally or preferably encircles all of the space.

15. A support structure according to claim 14 wherein the at least one continuous path forms a generally helical path around the side wall which traverses the inner and outer surfaces alternately, and optionally or preferably:wherein the at least one continuous path alternates between inner and outer surfaces of the side wall, optionally or preferably the at least one continuous path:extends in a first direction as the at least one continuous path extends along the outer surface from a first point near to, or on the first end to a second point near to or on the second end, andextends in a second direction, which is transverse to the first direction, as the at least one continuous path extends along the inner surface from the second point to a third point near to, or on the first end.

16. A support structure according to claim 15 when directly or indirectly dependent on claim 12 or 13, wherein the channels are connected to form a lengthened channel which follows the at least one continuous path.

17. A stator or rotor including a support structure according to any preceding claim and including the conductor or a plurality of conductors.

18. A support structure according to any one of claims 1 to 16 including a plurality of conductors and wherein the formations separate respective ones of the plurality of conductors from each other.

19. A support structure according to claim 18 when directly or indirectly dependent on claim 14 wherein each of the plurality of conductors follows a separate section of the at least one continuous path to complete at least one revolution around the side wall, or wherein the formations are connected to form a plurality of said continuous paths for the plurality of conductors, wherein respective ones of the plurality of said continuous paths are separate paths for respective ones of the plurality of conductors and the formations keep the plurality of conductors separated from each other.

20. A stator or rotor including a support structure according to claim 19 when directly or indirectly dependent on one of claims 8 to 11 wherein the projection members demarcate formations which separate the conductor or respective ones of the plurality of conductors, optionally or preferably the first set of projection members demarcate respective ones of the plurality of said continuous paths.

21. A stator or rotor including a support structure according to any preceding claim wherein the support structure is connected to a mounting member to form a stator or rotor.

22. A stator or rotor according to claim 21 wherein the support structure and mounting member are bonded together to form the rotor or stator, optionally or preferably the support structure and mounting member are made from the same material.

23. A support structure or stator / rotor according to any preceding claim including one or more or all of:a) wherein the formations include one or more retaining members which define respective openings between the formations for receiving respective portions of the conductor;b) wherein the conductor(s) are made from carbon nanotube yarn;c) wherein an insulative material covers the conductor(s) and the support structure to form a substantially sealed structure;d) wherein the conductor(s) do not have an insulative coating and / or the formations provide an insulative barrier between, or electrically isolate, the respective portions of the conductor or the plurality of conductors;e) wherein the support structure is generally annular shaped, and optionally or preferably cylindrical; andf) the support structure is manufactured using an additive manufacturing method.

24. An electric motor or generator including a stator formed from a support structure of any one of the preceding claims and a rotor, optionally or preferably the motor or generator has the stator and rotor arranged in an axial flux or raxial flux arrangement.

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