An electric motor

Abstract

An electric motor is disclosed. In an embodiment, the electric motor comprises a rotor unit, a stator unit coupled to the rotor unit and a first electrical connector. The first electrical connector is located within a through-opening of the stator unit such that the first electrical connector is externally accessible for mechanical and electrical interconnection to a second electrical connector. A stator unit and an electric motor assembly is also disclosed.

Description

AN ELECTRIC MOTORPRIORITY DOCUMENT

[0001] The present application for patent claims priority from Australian Provisional Patent Application No. 2024902690 entitled “An Electric Motor”, filed 28 August 2024, which is hereby expressly incorporated by reference herein in its entirety.FIELD

[0002] The present disclosure generally relates to electric motors. In atypical application, an embodiment of the present disclosure may be used in a motorised watercraft, such as a motorised foiling board.BACKGROUND

[0003] Electric motors typically include electrical connections to interconnect the motor to a power source and / or motor controller. For example, such electrical connections are sometimes used to electrically connect a power source to an electrical motor via a cable.

[0004] To connect the power source to the electrical motor, conventional electric motors include a cable or “flying leads” having terminations which are hardwired to the electric motor at one end. An opposite end of the cable includes an electrical connector housing electrical contacts, or individual electrical contacts, which are terminated or mated with electrical contacts of an electrical connector of the power source. In such an arrangement, the length of the cable or “flying leads” limits the distance that the power source and the motor may be separated by.

[0005] Furthermore, since an electrical connector typically houses its electrical contacts in a receptacle, lengthening or shortening the cable involves removing the receptacle from the cable, reterminating the electrical contacts and assembling the electrical connector. Such a process requires a person with appropriate skills and specialised tools to undertake.

[0006] In another arrangement, an electric motor may include terminals, such as separate studs or terminals (such as separate “positive” and “negative” studs), for electrically connecting to separate respective electrical contacts of a power lead or cable. In such arrangements, the connection between the respective terminals and contacts may be subject to stress and strain caused by movement of the power lead or cable, which could damage the terminals or contacts.

[0007] It would be desirable to provide a connection arrangement which addresses at least some of the above problems.SUMMARY

[0008] The following presents a simplified summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0009] In general terms, an embodiment of the present disclosure provides an electric motor comprising a stator unit having a first electrical connector which is located within a through-opening of the stator unit and which is externally accessible for mechanical and electrical interconnection to a second electrical connector.

[0010] A first aspect of the present disclosure provides an electric motor comprising: a rotor unit; a stator unit; and a first electrical connector located within a through-opening of the stator unit such that the first electrical connector is externally accessible for mechanical and electrical interconnection to a second electrical connector.

[0011] Before continuing further, it is to be noted that where used throughout this specification, references to the first electrical connector as being “located within a through-opening of the stator unit” are to be understood to denote that the elements (such as a set of electrical contacts) of the first electrical connector which mechanical and electrical interconnect to the second electrical connector are at least partially located within the through-opening. In this arrangement, when or as the connection (i.e. the mechanical and electrical interconnection) between the first electrical connector and the second electrical connector is formed, at least part of the second electrical connector is also located within, or projects into, the through-opening of the stator unit. An advantage of this arrangement is that the through-opening of the stator unit may provide mechanical support to the first electrical connector and the second electrical connector.

[0012] Mating the first electrical connector with the second electrical connector may involve a receptacle or “shroud” of the second electrical connector at least partially fitting in a space between the walls of the through-opening and the first electrical connector. In some embodiments, the fit may be a “loose fit” or “press fit”, such as an interference type fit.

[0013] In some embodiments, the first electrical connector is located within the through-opening so that the first electrical connector does not project externally outwardly from the stator unit. An advantage of this arrangement is that the first electrical connector is less susceptible to damage or breakage caused since the stator unit effectively shrouds the first electrical connector.

[0014] In certain embodiments, the electric motor further comprises: a removable securing means which, in use, is securable to the stator unit to hold the second electrical connector in mechanical and electrical interconnection with the first electrical connector.

[0015] In certain embodiments, the removable securing means is configured to clamp or hold the second electrical connector between the removable securing means and the stator unit without exerting a force on the first electrical connector.

[0016] In certain embodiments, the second electrical connector is connected to an electrical cable.

[0017] In certain embodiments, the second electrical connector is supported by a body. The body may be removably connected to the removable securing means such that removing the removable securing means from the stator unit disconnects the second electrical connector from the first electrical connector.

[0018] In certain embodiments, the removable securing means has a recess which is shaped to receive the body. The recess may be configured to apply a securing force which holds the body in interfacial relationship with an outer surface of the stator unit. The recess may be shaped to receive the body in an interlocking relationship which mechanically resists axial and / or radial movement of the body when the removable securing means is secured to the stator unit.

[0019] In certain embodiments, the second electrical connector is directly or indirectly attached to the removable securing means such that securing the removable securing means to the stator unit urges the second electrical connector to mechanically and electrically interconnect with the first electrical connector. The second electrical connector may be secured to or integrated with the removablesecuring means such that removing the removable securing means disconnects the second electrical connector from the first connector.

[0020] In certain embodiments, the removable securing means is adapted for removably attaching to an accessory item. The accessory item may comprise a mast, a fairing or a cowling. The removable securing means may be received within the accessory item for fixing thereto.

[0021] Yet another aspect of an embodiment of the disclosure provides a stator unit for an electric motor, comprising: a first electrical connector located within a through-opening of the stator unit such that the first electrical connector is externally accessible for mechanical and electrical interconnection to a second electrical connector when the stator unit is received within a shell housing a rotor.

[0022] Yet another aspect of an embodiment of the disclosure provides an electrical motor assembly comprising: an electric motor comprising: a rotor unit, a stator unit coupled to the rotor unit; and a first electrical connector located within a through-opening of the stator unit such that the first electrical connector is externally accessible for mechanical and electrical interconnection to a second electrical connector; an electrical cable having the second electrical connector at an end thereof, the second electrical connector in mechanical and electrical interconnection with the first electrical connector; and a body supporting the second electrical connector, the body being removably secured to the stator unit to hold the second electrical connector in mechanical and electrical interconnection with the first electrical connector.

[0023] These and other aspects of the invention will become more fully understood upon a review of the detailed description, which follows. Other aspects, features, and embodiments of the present invention will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments of the present invention in conjunction with the accompanying figures. While features of the present invention may be discussed relative to certain embodiments and figures below, all embodiments of the present invention can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments of the invention discussed herein. In similar fashion, whileexemplary embodiments may be discussed below as device, system, or method embodiments it should be understood that such exemplary embodiments can be implemented in various devices, systems, and methods.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments of the present disclosure will be discussed with reference to the accompanying drawings wherein:

[0025] Figure 1 is a perspective view of an electric motor according to an embodiment of the present disclosure;

[0026] Figure 2 is another perspective view of the electric motor shown in Figure 1 ;

[0027] Figure 3 is an exploded view of the electric motor of Figure 1 ;

[0028] Figure 4A is a sectional view of a section of the stator unit of the electric motor of Figure 1 with the windings not shown for clarity;

[0029] Figure 4B is a close-up sectional view of the stator unit of the electric motor of Figure 4A;

[0030] Figure 5 is an exploded sectional view of an electrical connection system according to an embodiment incorporating the electric motor of Figure 1;

[0031] Figure 6 is a sectional view of the electrical connection system of Figure 5 in an assembled state;

[0032] Figures 7 to 9 are perspective views of an electrical cable for incorporating in the electrical connection system of Figures 5 and 6 according to an embodiment;

[0033] Figures 10A and 10B are exploded views of the electrical cable of Figures 7 to 9 with a removable retaining means according to an embodiment;

[0034] Figure 11 shows the electrical cable and the removable retaining means of Figures 10A and 10B in an assembled state;

[0035] Figures 12 and 13 are exploded views showing the electrical connection system according to Figure 5 incorporating the electric motor of Figure 1 and a cowling;

[0036] Figures 14 and 15 show an electric motor and connection system according to an embodiment in an example application;

[0037] Figure 16 shows an electric motor and electrical connection system according to another embodiment in another example application;

[0038] Figures 17A to 17C show different views of the body shown in Figure 16; and

[0039] Figures 18A to 18C show an assembly sequence for assembling an electrical motor assembly including the electric motor and body shown in Figure 16 and attaching the assembly to a mast.DETAILED DESCRIPTION OF EMBODIMENTS

[0040] Referring initially to Figures 1 through to 6 where there is illustrated an electric motor 1 according to an embodiment of the disclosure. The electric motor 1 shown here is a brushless electric motor 10. However, it will be appreciated that other types of electric motors may be used.

[0041] The illustrated brushless motor 10 is a waterproof brushless motor comprising a stator unit 12 having a first electrical connector 14 housing a first set of electrical contacts 16 in a receptacle 18.

[0042] In the present case, the brushless motor 10 is a 150KV 80KV waterproof brushless motor suitable for providing underwater thrust for a standup foiling paddle board using a propeller 300 (ref. Figures 14 and 15) connected to propeller mounting holes 5 (ref. Figure 2). However, it will be appreciated that other embodiments may use a different electric motor.

[0043] The first electrical connector 14 shown here is located within a through-opening 20 (ref. Figures 4A and 4B) of the stator unit 12 such that when the stator unit 12 is assembled with a rotor unit 2 of the electric motor 1, the first electrical connector 14 is externally accessible for mechanical and electrical interconnection to a second electrical connector 22 (ref. Figures 5 and 6). When so interconnected, the first set of electrical contacts 16 of the first electrical connector 14 mate with a second set of electrical contacts 24 of the second electrical connector 22. The first electrical connector14 may be secured to the interior of the through-opening 20 by suitable means such as by glueing, fitting (such as by an interference fit) or the like.

[0044] Returning now to Figure 3, in the present case, the stator unit 12 of the brushless electric motor 10 comprises a stator 32 having a first arcuate outer surface 34 extending about a longitudinal axis A. There is a longitudinally extending bore 36 (ref. Figure 4A) which accommodates bearings 38, 40, 42.

[0045] As will be appreciated by a person skilled in the art, a stator for a brushless electric motor comprises a stator core and stator windings shown here generally as CW. In the present case, the stator core is a magnetic structure comprised of stacked laminations of ferromagnetic material, such as silicon steel, to reduce eddy current losses. The stator core is configured with a plurality of teeth and slots (not shown) to accommodate the stator windings. The stator windings comprise electrically conductive coils disposed within the stator slots and are configured to generate a rotating magnetic field when energised.

[0046] The first arcuate outer surface 34 of the stator unit 12 defines an outer periphery of a first cylindrical section 50 of the stator unit 12. There is a second cylindrical section 54 having a second arcuate outer surface which is coaxial with, and projects radially outwardly with respect to, the first cylindrical section 50.

[0047] In the present case, the second cylindrical section 54 of the stator unit 12 forms a head 56 of the stator unit 12 having an outside diameter which exceeds that of the first cylindrical section 50 such that there is a lip 58 formed at the junction of the first cylindrical section 50 and the second cylindrical section 54. This lip 58 extends continuously about the first arcuate outer surface 34.

[0048] Figures 4A and 4B show a sectional view of the stator unit 12 with the core and windings CW (ref. Figure 3) omitted for clarity. During assembly of the brushless electric motor 10, a rotor unit 2 (ref. Fig 3) comprising a rotor 44 (ref. Figure 3) and a shell 60 is coupled to stator unit 12 by sliding the rotor 44 (ref. Figure 3) into the bore 36 of the stator unit (ref. Figure 4A) from a first end 46 of the stator unit 12. As the rotor 44 is slid into the bore 36 an inner surface 64 of cylindrical shell 60 slidably receives the first arcuate outer surface 34 of the stator unit 12 until a front edge 62 of the shell 60 is positioned proximal to the lip 58. When so positioned, the stator unit 12 is coupled with the shell 60 and the shaft 48 of the rotor 44 is received within the bearings 38, 40, 42 so that the rotor 44 of the rotor unit 2 will rotate about the longitudinal axis A.

[0049] The receptacle 18 of the first electrical connector 14 houses the first set of electrical contacts 16 (ref. Figure 4B). These electrical contacts 16 are electrically connected to the stator 32 as required using suitable wired interconnections (not shown). In the present case, the first electrical connector 14 is a keyed 3-pole MR30 ‘socket’ type connector having a polyamide receptacle 18 which houses the first set of electrical contacts 16. In this case, the first set of electrical contacts 16 comprise solder buckets for terminating ends of the wired interconnections. It will of course be appreciated that other types of terminations may be used.

[0050] Turning now to Figures 5 and 6, in embodiments, the second electrical connector 22 is supported by a body 26 which is adapted to be removably held in interfacing relationship with an outer surface 28 of the stator unit 12 using a removable securing means 30. Removable securing means 30 is attachable to the stator unit 12 to position and hold the second electrical connector 22 in mechanical and electrical interconnection with the first electrical connector 14. When secured in this way, the electrical and mechanical interconnection between the first electrical connector 14 and the second electrical connector 22 may be less vulnerable to mechanical stresses since the body 26 supporting the second electrical connector 22 is fixedly secured between the removable securing means 30 and the outer surface 28 of the stator unit 12 in a way which locates and holds the second electrical connector 22 in mechanical and electrical interconnection with the first electrical connector 14.

[0051] In the present case, the body 26 is attached to the removable securing means 30 using a fastener 142 such that removing the removable securing means 30 removes (i.e., disconnects) the second electrical connector 22 from the first electrical connector 14.

[0052] The second electrical connector 22 shown here is illustrated as a keyed 3-pole MR30 ‘male’ type connector with a polyamide receptacle. In the present case, the second electrical connector 22 is encapsulated within a body 26 of a suitable polymetric material. Accordingly, in the illustrated example it is the encapsulation of the electrical connector 22 within the body 26 that supports the electrical connector 22. It will be appreciated that different types of mating electrical connectors and different support arrangements may be used. For example, in some embodiments, the second electrical connector 22 may be glued, fastened (using suitable fasteners), fitted (such as by way of an interference fit) or the like to the body 26.

[0053] In the present case, the fastener 142 secures the body 26, and thus the second electrical connector 22, to the removable securing means 30 prior to mating the second electrical connector 22 with the first electrical connector 14. In this way, the body 26 and removable securing means 30assembly may be secured in interfacing relationship with the outer surface 28 of the stator unit 12 using fasteners 114 to connect the second electrical connector 22 to the first electrical connector 14.

[0054] In the illustrated embodiment, the first electrical connector 14 is located within the through- opening 20 within the head 56 of the stator unit 12 so that the first electrical connector 14 is recessed relative to the outer surface 28. When so located, the first set of electrical contacts 16 of the first electrical connector 14 are externally accessible to mate with the second set of electrical contacts 24 of the second electrical connector 22. In this way, the second electrical connector 22 is at least partially received by or within the through-opening 20 of the stator unit 12 as it is mated with the first electrical connector 14.

[0055] Returning now to Figures 4A and 4B, in the depicted embodiment, locating the first electrical connector 14 within the through-opening 20 involves inserting the receptacle 18 of the first electrical connector 14 into the through-opening 20 via a first aperture 68 accessible from an opposite side 72 (which in this case is a rear side) of the head 56 relative to the outer surface 28 (which in this case is a front side).

[0056] In other embodiments it is possible that the first electrical connector 14 may be inserted for location within the through-opening 20 via a second aperture 70 of the through-opening 20 disposed on the same side as of the head as the outer surface 28, but nevertheless still be located within the through-opening 20 of the stator unit 12.

[0057] In the present case, when the first electrical connector 14 is located within the through- opening 20, the receptacle 18 of the first electrical connector 14 does not project outwardly from the outer surface 28. An advantage of locating the first electrical connector 14 within the through- opening 20 of the stator unit 12 in this way is that the stator unit 12 protects the receptacle 18 of the first electrical connector 14 from damage. Furthermore, locating the first electrical connector 14 within the through-opening 20 provides mechanical support to the receptacle 18 of the first electrical connector 14 via an interfacing relationship which involves two surfaces of an interior of the through- opening 20, as will be described in more detail below.

[0058] In some embodiments, once the first electrical connector 14 is located within the through- opening 20 it may be secured within the through-opening 20 of the stator unit 12 by a suitable adhesive or other means. One example of a suitable adhesive is an epoxy resin. In certain embodiments, the first electrical connector 14 may be located and secured within the through-opening 20 using an interference type fit.

[0059] With reference now to Fig. 4B, the depicted through-opening 20 comprises a first receiving region 73 which extends between the first aperture 68 and an internal flange 74. The first receiving region 73 shown here is shaped to receive an outer band 78 of the receptacle 18 of the first electrical connector 14. In the present case, the outer band 78 comprises a ribbed outer band 78 having an edge 80 which abuts against the flange 74 when the first electrical connector 14 is located within the through-opening 20.

[0060] The flange 74 is configured to accommodate and extend about a longitudinal outer extent of the receptacle 18 of the first electrical connector 14 in a contacting relationship. There is a second region 82 of the through-opening 20 which extends from the flange 74 towards the second aperture 70. The second region 82 has an inside cross section which is shaped and sized to provide a clearance 84 (ref. Figure 5) for receiving a shroud portion 86 (ref. Fig, 5) of the receptacle of the second electrical connector 22 so that the shroud portion 86 can slidably receive a correspondingly shaped portion of the receptacle 18 of the first electrical connector 14 as the respective electrical contacts 16, 24 of the first electrical connector 14 and the second electrical connector 22 are mechanically and electrically interconnected during mating.

[0061] A third region 88 of the through-opening 20 extends longitudinally toward the outer surface 28, and radially outwardly relative to the second region 82. A recessed surface 90 (ref. Fig 4A) provides a continuous ledge onto which a sealing means 94 (ref. Fig. 5), such as an O-Ring or washer is seated to provide protection from moisture ingress when the body 26 is secured to the stator unit 12.

[0062] In the illustrated embodiment, the sealing means 94 is an O-ring having a cross-sectional diameter which is sized so that the O-ring is compressed, at least to some extent between the recessed surface 90 and the body 26 supporting the second electrical connector 22 as the removable securing means 30 is secured to the stator unit 12. In the present case, when so secured a spacing between the body 26 and the recessed surface 90 is less than the cross-sectional diameter of the O-ring when in an uncompressed state.

[0063] An advantage of this configuration is that when the second electrical connector 22 is secured to the stator unit 12 to hold the second electrical connector 22 in mechanical and electrical interconnection with the first electrical connector 14, the sealing means 94 is compressed between the body 26 supporting the second electrical connector 22 and the recessed surface 90, instead of between the receptacle 18 of the first electrical connector 14 and the body 26 of the second electrical connector22. In this way, the compressive force which is exerted on the sealing means 94 is not transferred to the first electrical connector 14.

[0064] Compression of the sealing means 94 prevents, or at least reduces the likelihood of, moisture ingress into the stator unit 12 through the second aperture 70 during normal use as well as reducing the likelihood of moisture ingress into the electrical contacts 16, 24 of the first electrical connector 14 and the second electrical connector 22 respectively. Furthermore, since the compressive force which is applied to compress the sealing means 94 is not applied or transferred to the first electrical connector 14, the likelihood of such forces dislodging the first electrical connector 14 from the through-opening 20 is reduced.

[0065] Turning now to Figures 7 to 9, in embodiments, the second electrical connector 22 is connected to a cable assembly 204 which electrically connects the contacts 24 of the second connector 22 with contacts of a cable connector 140 via terminations 66. In use, the cable connector 140 may be connected to a power and / or control unit which provides power and control signals to the electric motor 10 via the cable 204.

[0066] As shown in Fig.5, the terminations 66 of the second connector 22 and a length of the cable 204 are encapsulated within the body 26. Encapsulating the terminations 66 of the second connector 22 and the length of the cable 204 within the body 26 provides strain relief for the cable 204 and protects the terminations 66 from the external environment, such as water or dust.

[0067] The removable securing means 30 is securable to the head 56 of the stator unit 12 to hold the second electrical connector 22 in mating relationship with the first electrical connector 14 and prevent the second electrical connector 22 from disconnecting from the first electrical connector 14. With reference now to Figures 10A, 10B and 11, the removable securing means 30 comprises a generally puck-shaped body 98 having a first side 100 for contacting the outer surface 28 of the head 56 of the stator unit 12 and an opposite side 102. In the present case, a pair of spaced apart projections 104 extend from the opposite side 102. The function of the projections 104 will be described in more detail below.

[0068] Continuing with reference to Figures 10A and 10B, there is a recess 106 located on the first side 100 of the removable securing means 30. The recess 106 shown here is sized and located for alignment with the body 26 supporting the second electrical connector 22 when the removable securing means 30 is positioned for securing to the stator unit 12 to mate the second electrical connector 22 with the first electrical connector 14. When so aligned and positioned, and withreference to Fig. 11, at least a portion of the body 26 supporting the second electrical connector 22 is received within the recess 106.

[0069] In the present case, when the second electrical connector 22 is received within the recess 106 a fastener 142 (ref. Fig. 5) is used to secure the second electrical connector 22 to the removable securing means 30 prior to mating the second electrical connector 22 with the first electrical connector 14.

[0070] Once the second electrical connector 22 and the first electrical connector 14 are mated, the removable securing means 30 is secured to the stator unit 12 using fasteners 114 (ref. Fig,.12) and tightened so that the recess 106 applies a securing force which urges the body 26 supporting the second electrical connector 22 to maintain or hold an interfacial relationship with the outer surface 28. In embodiments, this securing force also holds the second electrical connector 22 in mating relationship with the first electrical connector 14 by securing the mechanical and electrical interconnection therebetween.

[0071] In the present case, the securing force is applied due to a clamping -type action of the removable securing means 30 and the stator unit 12 which has the effect of clamping the second electrical connector 22 therebetween without exerting the securing force on the first electrical connector 14. In the present case, this clamping effect holds the second electrical connector 22 in the mechanical and electrical interconnection with the first electrical connector 14.

[0072] Continuing now with reference to Fig. 10B, in the present case, the recess 106 has a perimeter 110 which is shaped to conform with the shape of a portion of the perimeter of the body 26 supporting the second electrical connector 22 such that receiving the body 26 of the second electrical connector 22 within the recess 106 forms an interlocking relationship therebetween.

[0073] In embodiments, the recess 106 and the shape of the body 26 are configured so that the interlocking relationship mechanically resists axial and / or radial movement of the body 26 supporting the second electrical connector 22 when the removable securing means 30 is secured to the stator unit 12. In other words, in certain embodiments, the removable securing means 30 is configured to apply a securing force to the body 26 of the second electrical connector 22 (which holds the second electrical connector 22 in mating relationship with the first electrical connector 14) and form an interlocking relationship with the body 26 of the second electrical connector 22 of a type which mechanically resists axial and / or radial movement of the body 26 of the second electrical connector 22.

[0074] An advantage of an embodiment which mechanically resists axial and / or radial movement of the body 26 supporting the second electrical connector 22 is that axial and / or radial forces applied to the body 26 supporting the second electrical connector 22 in normal use are not transferred to the first electrical connector 14.

[0075] Securing the removable securing means 30 to the stator unit 12 may be performed using any suitable means. In the depicted embodiment, the stator unit 12 includes threaded bores 112 and fasteners 114. In this non-limiting example, the fasteners 114 are inserted through bores 118 (ref. Fig. 13) in the removable securing means 30 and into the threaded bores 112 for tightening to secure the removable securing means 30 to the stator unit 12.

[0076] Returning now to Figures 10A and 10B, there is an opening 116 in the removable securing means 30 which is shaped to allow a portion of the body 26 supporting the second electrical connector 22 to project outwardly from the removable securing means 30 in the axial and / or radial directions. In this way, when the second electrical connector 22 is secured by the removable securing means 30, an edge of the opening 116 surrounds the portion of the body 26 supporting the second electrical connector 22 projecting outwardly from the recess 106 in the axial and radial directions.

[0077] Providing an opening 116 which allows the body supporting of the second electrical connector 22 to project outwardly from the recess 106 provides a path for the electrical cable 204 connected to the electrical contacts of the second electrical connector 22 to be routed externally to the removable securing means 30.

[0078] It can be seen that in the illustrated embodiment, the recess 106 is shaped so that when the second electrical connector 22 is located within the recess 106, the shroud 86 of the second electrical connector 22 projects in the direction of and for alignment with the receptacle 18 of the first electrical connector 14 to permit mating.

[0079] Turning now to Figures 12 and 13, as described above, in the illustrated embodiment the removable securing means 30 includes a pair of projections 104 in the form of posts 120, 122. In the present case, the posts 120, 122 are configured to allow a fairing or cowling 130 to be attached to the removable securing means 30 and thus to the motor unit 10.

[0080] That is to say, that in addition to providing a means for removably securing the second electrical connector 22 to the stator unit 12 to retain a mechanical and electrical interconnection between the second electrical connector 22 and the first electrical connector 14, in certainembodiments the removable securing means 30 also provides a means of removably attaching the electric motor assembly to an accessory, such as a fairing or cowling 130. An advantage of this approach is that it reduces the need for additional mounting hardware to removably attach a fairing or cowling 130 to the motor unit 10.

[0081] In the present case, the posts 120 are fitted with threaded inserts 124 for receiving threaded fasteners 126 inserted through a body of the fairing or cowling 130. However, it will be appreciated that other arrangements are possible.

[0082] An advantage of embodiments of the present invention is that they allow for the removal and / or replacement of an electrical cable 204 having the second electrical connector 22 at an end thereof which is connected to the first electrical connector 14 of the electric motor 10. In certain application, being able to remove and / or replace an electrical cable 204 in this way allows the electric motor 10 to be used with electrical cables 204 of different lengths, as may be required for a particular application, such as for a propulsion system for a watercraft. Furthermore, being able to remove and / or replace an electrical cable 204 may allow for replacement of a damaged electrical cable 204 without the need to replace the electric motor 10.

[0083] Embodiments of the present application are expected to find particular application in the field of propulsion systems for motorised foiling watercraft. The disclosed arrangement may reduce stress on electrical contacts, enhances durability, and simplify integration with accessories like masts or cowlings, offering advantages in serviceability, reliability, and versatility for motorised foiling watercraft applications.

[0084] Figures 14 and 15 show an example application in which the electric motor 10 is fitted to a mast 200 of a foiling board 202 and an electrical cable 204-1 interconnects the motor unit 10 to a power module 206 secured to an underside 208 of the foiling board 202. In this application, interchanging the electrical cable 204-1 with a longer or shorter cable 204-2 allows the electric motor assembly to be repositioned along the length of the mast 200 away from or towards the power module 206 to which the electric motor 10 is connected via the cable 204 as may be required for different rider preferences.

[0085] Figure 16 shows another example application in which an electric motor assembly including the above-described electric motor 10 is secured to the mast 200 at a fixed position. In this example, the electrical cable 204-1 is integrated within the mast 200. The mast 200 has a rearward opening receptacle 324 which is configured to receive and secure a body 302. Body 302 is removablysecurable to the stator unit 12 of the electric motor assembly. Electrical cable 204-1 interconnects the electric motor 10 to a power module 206. In this example, because the electric motor 10 is integrated within the mast 200 at a fixed point, different length cables 204 are not required.

[0086] Figures 17A to 17C illustrate the above-described body 302 in more detail. The body 302 is similar in function to the combination of the body 26 and the removable securing means 30 described above (i.e, when the body 26 and the removable securing means 30 are connected) in that it supports the second electrical connector 22 (ref. Figure 16) for mechanical and electrical interconnection with the first electrical connector 14 of the electric motor 10 and is removably secured to the stator unit 12.

[0087] In the depicted example, the body 302 supports the second connector 22 within a through-hole 300. The second connector 22 is pushed into the through-hole and secured to the body 302 using a suitable adhesive, such as an epoxy resin. There are a pair of projections 304 in the form of posts 320, 322. In the present case, the posts 320, 322 are configured to be received within the internal receptacle 324.

[0088] Turning now to Figures 18A to 18B, during assembly, the body 320 is aligned with the electric motor 10 to mate the second connector 22 with the first connector 14. When so mated, a securing means (shown here as fasteners 308) secures the body 302 in interfacing relationship with the stator unit 12 to hold the second electrical connector 22 in mechanical and electrical interconnection with the first electrical connector 14. An O-ring (not shown) provides the same sealing function as described above.

[0089] The body 302 of the assembled electric motor assembly is then inserted into the receptacle 324 to place holes 306 in the mast 200 in co-axial alignment with holes 310 in the body 302. Once so aligned, a securing means, such as a fastener, is inserted through the holes 306 in the mast 200 and the holes 310 in the post 320, 322 to removably secure the electric motor assembly to the mast 200.

[0090] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that such prior art forms part of the common general knowledge.

[0091] It will be understood that the terms “comprise” and “include” and any of their derivatives (e.g. comprises, comprising, includes, including) as used in this specification, and the claims that follow, is to be taken to be inclusive of features to which the term refers, and is not meant to exclude the presence of any additional features unless otherwise stated or implied.

[0092] In some cases, a single embodiment may, for succinctness and / or to assist in understanding the scope of the disclosure, combine multiple features. It is to be understood that in such a case, these multiple features may be provided separately (in separate embodiments), or in any other suitable combination. Alternatively, where separate features are described in separate embodiments, these separate features may be combined into a single embodiment unless otherwise stated or implied. This also applies to the claims which can be recombined in any combination. That is a claim may be amended to include a feature defined in any other claim. Further a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

[0093] It will be appreciated by those skilled in the art that the disclosure is not restricted in its use to the particular application or applications described. Neither is the present disclosure restricted in its preferred embodiment with regard to the particular elements and / or features described or depicted herein. It will be appreciated that the disclosure is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope as set forth and defined by the following claims.

Claims

CLAIMS1. An electric motor comprising: a rotor unit; a stator unit coupled to the rotor unit; and a first electrical connector located within a through-opening of the stator unit such that the first electrical connector is externally accessible for mechanical and electrical interconnection to a second electrical connector.

2. An electric motor according to claim 1 wherein the first electrical connector does not project externally outwardly from the stator unit.

3. An electric motor according to claim 1 or 2 further comprising: a removable securing means which, in use, is securable to the stator unit to hold the second electrical connector in mechanical and electrical interconnection with the first electrical connector and the second electrical connector.

4. An electric motor according to claim 3 wherein the removable securing means is configured to clamp or hold the second electrical connector between the removable securing means and the stator unit without exerting a force on the first electrical connector.

5. An electric motor according to claim 3 or 4 wherein the second electrical connector is connected to an electrical cable, wherein the second electrical connector is supported by a body, and wherein the body is removably connected to the removable securing means such that removing the removable securing means from the stator unit disconnects the second electrical connector from the first electrical connector.

6. An electric motor according to claim 5 wherein the removable securing means has a recess which is shaped to receive the body.

7. An electric motor according to claim 6 wherein the recess has a surface for applying a securing force to the body to hold the body in interfacial relationship with an outer surface of the stator unit.

8. An electric motor according to claims 6 or 7 wherein the recess is shaped to receive the body in an interlocking relationship which mechanically resists axial and / or radial movement of the body when the removable securing means is secured to the stator unit.

9. An electric motor according to claim 3 wherein the second electrical connector is secured to or integrated with the removable securing means such that removing the removable securing means disconnects the second electrical connector from the first connector.

10. An electric motor according to claim 9 wherein the removable securing means is adapted for removably attaching to an accessory item.

11. An electric motor according to claim 10 wherein the accessory item comprises: a mast; or a fairing; or a cowling.

12. An electric motor according to claim 11 wherein the removable securing means is received within the accessory item for fixing thereto.

13. A propulsion system for a watercraft, the system comprising: an electric motor according to any one of claims 1 to 12; an electrical cable having the second electrical connector at an end thereof, the second electrical connector in mechanical and electrical interconnection with the first electrical connector, wherein the electrical cable is connected to a power supply or a motor controller at an opposite end of electrical cable.

14. A watercraft including a propulsion system according to claim 13.

15. A stator unit for an electric motor, comprising a first electrical connector located within a through-opening of the stator unit such that the first electrical connector is externally accessible for mechanical and electrical interconnection to a second electrical connector when the stator unit is received within a shell housing a rotor.

16. A stator unit according to claim 15 wherein the first electrical connector is located within the through-opening so that the first electrical connector does not project externally outwardly from the stator unit.

17. An electrical motor assembly comprising: an electric motor comprising: a rotor unit, a stator unit coupled to the rotor unit; anda first electrical connector located within a through-opening of the stator unit such that the first electrical connector is externally accessible for mechanical and electrical interconnection to a second electrical connector; an electrical cable having the second electrical connector at an end thereof, the second electrical connector in mechanical and electrical interconnection with the first electrical connector; and a body supporting the second electrical connector, the body being removably secured to the stator unit to hold the second electrical connector in mechanical and electrical interconnection with the first electrical connector.

18. An electrical motor assembly according to claim 17 further comprising a removable securing means which is secured to the stator unit to hold the second electrical connector in mechanical and electrical interconnection with the first electrical connector, wherein the removable securing means is configured to hold the second electrical connector between the removable securing means and the stator unit without exerting a force on the first electrical connector.

19. An electrical motor assembly according to claim 17 wherein the body is removably secured to the stator unit by a removable securing means which directly secures the body to the stator unit.

20. An electrical motor assembly according to claim 18 wherein the removable securing means is configured to attach to an accessory item to thereby attach the electric motor to the accessory item.

21. An electrical motor assembly according to claim 19 wherein the body is configured to attach to an accessory item to thereby attach the electric motor to the accessory item.

22. An electric motor assembly according to any one of claims 17 to 21 wherein the first electrical connector does not project externally outwardly from the stator unit.

23. An electric motor assembly according to any one of claims 17 to 22 wherein the second electrical connector is at least partially received by or within the through-opening of the stator unit.

24. An electric motor assembly according to claim 21 wherein the accessory item comprises: a mast; or a fairing; or a cowling.

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