ELECTRICAL MACHINE SYSTEM AND MOBILITY DEVICE COMPRISING SUCH AN ELECTRICAL MACHINE SYSTEM

Abstract

- The invention relates to an electrical machine system (100) comprising: an electrical machine (102); an inverter (104); a wall (108) having a hole (116), wherein the electrical machine (102) and the inverter (104) extend on two sides of the wall (108), respectively; a plurality of busbars connecting the electrical machine (102) and the inverter (104), wherein at least one (114) of the busbars comprises a first portion (120) extending on the side of the electrical machine (102), a second portion (124) extending on the side of the inverter (104), and a rigid central portion (126) connecting the first and second portions (120, 124), wherein the central portion (126) passes through the hole (116) of the wall (108);wherein the first portion (120) and / or the second portion (124) comprise a braided portion, and a sealing device (128) between the wall (108) and the central portion (126) of the busbar (114);

Description

Technical FieldThe present invention relates to an electric machine system and a mobility device comprising such an electric machine system.The invention can be used in particular in a mobility device. A mobility device is, for example, a motorized land vehicle, a train, an aircraft or else a drone. A motorized land vehicle is, for example, a motor vehicle, a motorcycle, a motorized bicycle or a motorized wheelchair.PRIOR ARTAn electric machine system includes an electric machine and an inverter connected to each other by different bus bars. As is known, a single common housing is used for the electric machine and the converter. However, they are usually positioned in two separate spaces of the housing. The two spaces must be hermetically sealed from each other due to the various requirements required for each. For example, the requirement regarding humidity level or cleanliness may be different in the inverter and the electric machine.Thus, it is necessary to pass the bus bars through the wall separating the two spaces. The relative position of the electric machine and the inverter may deviate from the design due to manufacturing tolerances and / or may change during use due to thermal expansion resulting from the temperature difference between two spaces.The invention aims to overcome the above problems at least in part.Disclosure of the InventionThe invention relates to an electric machine system comprising:an electric machine; anda converter;a wall having a hole, wherein the electric machine and the inverter extend on two sides of the wall, respectively;a plurality of bus bars connecting the electric machine and the inverter, at least one of the bus bars comprising a first portion extending on the side of the electric machine, a second portion extending on the side of the inverter, and a rigid central portion connecting the first and second portions, the central portion passing through the hole of the wall; at least one of the first portion and the second portion comprising a braided portion; anda sealing device between the wall and the central portion of the busbar.Thanks to the invention, the busbar can compensate for the change in relative position and at the same time keep the two spaces hermetically sealed. By hermetically sealing both spaces, it can be ensured that the components function properly and the specific requirements of each component are fulfilled separately. For example, to ensure that no transfer of a cooling fluid of the electric machine to a dry inverter cavity may take place.In particular, the sealing can be effective thanks to the rigid central portion.The invention may also include one or more of the following optional features in any technically possible combination.Optionally, the first portion and the second portion comprise a braided portion, wherein the central portion connects the first and second braided portions.Also optionally, the sealing device comprises: - a sleeve surrounding the central portion of the busbar, the sleeve covering the hole of the wall; - a sealing ring extending between the sleeve and the wall, the sealing ring surrounding the hole of the wall; and - a pushing device configured to push the sleeve towards the wall such that the sleeve pushes on the sealing ring.Optionally, the sleeve also extends on the converter side of the wall.Also optionally, the sliding device comprises at least one screw which passes through the sleeve and is screwed into the wall.Also optionally, the sealing device comprises a sealing ring inserted between the central portion of the busbar and the wall.Also optionally, the electric machine system comprises a housing defining an interior space, wherein the wall divides the interior space into two spaces, wherein the electric machine extends in the first space, wherein the inverter extends in the second space.Optionally, the busbar is also produced from copper.The invention also relates to a mobility device comprising an electric machine system according to the invention.Brief Description of the DrawingsThe invention will be better understood from the following description, given purely by way of example and with reference to the accompanying drawings, in which:FIG. 1 is a schematic view of a first example of an electric machine system according to the invention; andFIG. 2 is a schematic view of a second example of an electric machine system according to the invention.Detailed DescriptionReferring now to FIG. 1, an electric machine system 100 according to the invention will be described. The electric machine system 100 is configured for use in a mobility device, for example.The electric machine system 100 initially comprises an electric machine 102 having a plurality of phases. The electric machine 102 may act as a motor and / or a generator.The electric machine system 100 further comprises an inverter 104 configured to provide the phase voltages U, V, W from a DC voltage source (not shown).The electric machine system 100 further includes a housing 106 defining an interior space and a wall 108 dividing the interior space into two spaces 110, 112. The electric machine 102 and the inverter 104 extend respectively on two sides of the wall 108. More specifically, the electric machine 102 extends in the first space 110 and the inverter 104 extends in the second space 112.The electric machine system 100 further comprises a plurality of busbars, of which only one is illustrated in FIG. 1 and is denoted by 114. The bus bars 114 connect the inverter 104 to the respective phases of the electric machine 102 to conduct the phase voltages U, V, W between the inverter 104 and the respective phases of the electric machine 102.In order for the bus bar 114 to pass through the wall 108, the wall 108 is provided with a hole 116.The bus bar 114 includes, in the first space 110, a first rigid connection portion 118 connected to the electric machine 102 and a first flexible braided portion 120 connected to the first rigid connection portion 118.Similarly, in the second space 112, the bus bar 114 includes a second rigid connection portion 122 connected to the inverter 104 and a second flexible braided portion 124 connected to the second rigid connection portion 122.The bus bar 114 further includes a rigid central portion 126 connecting the first and second braided portions 120, 122, the rigid central portion 126 passing through the hole 116 of the wall 108. The rigid portions 118, 122, 126 are preferably solid, i.e., not hollow.The electric machine system 100 further includes a sealing device 128 between the wall 108 and the central portion 126 of the bus bar 114.For example, as shown, the sealing device 128 includes a sleeve 130 surrounding the central portion 126 of the bus bar 114. The sleeve 130 is configured watertight to prevent liquid, such as water, from spreading along the central portion 126 of the bus bar 114 from one of the spaces 110, 112 into the other.Also, to prevent the spread of liquid, such as water, around the sleeve 130, the sleeve 130 is positioned to cover the hole 116 of the wall 108, and the sealing device 128 further comprises a sealing ring 132 inserted between the sleeve 130 and the wall 108, the sealing ring 132 surrounding the hole 116 of the wall 108. The seal ring 132 is configured watertight to prevent liquid from passing between the wall 108 and the sleeve 130. The sealing device 128 further includes a pusher 134 configured to push the sleeve 130 toward the wall 108 such that the sleeve 130 pushes the seal ring 132 against the wall 108. For example, the slider 134 is shown to include one or more screws 136 that pass through the sleeve 130 and are threaded into the wall 108.In some embodiments, the sleeve 130 includes a single molding around the central portion 126 of the bus bar 114.In some embodiments, the sleeve 130 is shown to include a single molding 138 around the central portion 126 of the bus bar 114 and a second molding 140 around the first molding 138. For example, the first molding is made of a soft material and the second molding is made of a hard material. The hard molding material is used for fixation and structural strength, and the softer material is used for securing tightness during thermal expansion so that the elastic material can follow the deformation of the bus bars.Referring to FIG. 2, in some embodiments, the sealing device 128 includes a sealing ring 202 inserted between the wall 108, for example as shown, an edge (i.e., a width) of the wall around the perimeter of the hole 116, and the central portion 126 of the bus bar 114.The bus bar(s) other than the bus bar 114 may have the same structure as the bus bar 114 described above. All busbars 114 may pass through respective holes in wall 108 or through the same hole, in which case all busbars 114 may be surrounded by the same single sleeve.Finally, it is noted that the invention is not limited to the embodiments described above. Indeed, it will be apparent to those skilled in the art that various modifications may be made to the above-described embodiments in view of the teachings just disclosed.The terms used in the detailed presentation of the invention made above are not to be interpreted as limiting the invention to the embodiments presented in the present description, but must be interpreted as including all equivalents that are predicted by those skilled in the art using their general knowledge to implement the teaching just disclosed.

Claims

An electric machine system (100) comprising: - an electric machine (102); - an inverter (104); - a wall (108) having a hole (116), the electric machine (102) and the inverter (104) extending on two sides of the wall (108), respectively; - a plurality of bus bars connecting the electric machine (102) and the inverter (104), at least one (114) of the bus bars comprising a first portion (120) extending on the side of the electric machine (102), a second portion (124) extending on the side of the inverter (104), and a rigid central portion (126) connecting the first and second portions (120, 124), the central portion (126) passing through the hole (116) of the wall (108); wherein at least one of the first portion (120) and the second portion (124) comprises a braided portion, and a sealing device (128) between the wall (108) and the central portion (126) of the bus bar (114).The electric machine system (100) of claim 1, wherein the first portion (120) and the second portion (124) comprise a braided portion, wherein the central portion (126) connects the first and second braided portions (120, 124).The electric machine system (100) according to claim 1 or 2, wherein the sealing device (128) comprises: - a sleeve (130) surrounding the central portion (126) of the bus bar (114), the sleeve (130) covering the hole (116) of the wall (108); - a sealing ring (132) extending between the sleeve (130) and the wall (108), the sealing ring (132) surrounding the hole (116) of the wall (108); and - a pushing device (128) configured to push the sleeve (130) towards the wall (108) such that the sleeve (130) pushes the sealing ring (132).The electric machine system (100) of claim 3, wherein the sleeve (130) extends on the inverter side of the wall (108).The electric machine system (100) of claim 3 or 4, wherein the pusher (134) comprises at least one screw (136) passing through the sleeve (130) and threaded into the wall (108).The electric machine system (100) according to claim 1 or 2, wherein the sealing device (128) comprises a sealing ring (202) inserted between the central portion (126) of the busbar (114) and the wall (108).The electric machine system (100) of any of claims 1 to 6, further comprising a housing (106) defining an interior space, wherein the wall (108) divides the interior space into two spaces (110, 112), wherein the electric machine (102) extends in the first space (110), wherein the inverter (104) extends in the second space (112).The electric machine system (100) according to any one of claims 1 to 7, wherein the bus bar (114) is made of copper.A mobility device comprising an electric machine system (100) according to any one of claims 1 to 8.

Images