SUPPORT DEVICE FOR A STATOR IN A HOUSING

Abstract

A SUPPORT DEVICE FOR A STATOR IN A HOUSING This subject relates to a rotating electrical machine (100) comprising a rotor, a stator (104), a housing (110), and a support device (112). The rotor can rotate about an axis of rotation (116). The stator (104) is arranged coaxially with the rotor. The stator (104) comprises a stator core (106) and a winding (108a; 108b). The housing (110) comprises a chamber defined by a closed end (120) at one end and an open end (118) at the other. The chamber receives, at least in large part, the rotor and the stator (104). The inner surface of the housing and the outer surface of the stator core form an annular space (114) that extends axially between the two. The support device (112) is at least partially disposed between the stator core (106) and the housing (110). The support device (112) covers at least partially the annular space (114).The support device (112) is adapted to at least limit the radial displacement of the stator core (106) relative to the rotational axis (116). Figure for the abbreviation: Fig. 1.

Description

Title of the invention: SUPPORT DEVICE FOR A STATOR IN A HOUSING FIELD OF THE INVENTION

[0001] The present subject matter relates to a support device for a stator in a housing of a rotating electrical machine.

[0002] CONTEXT

[0003] Rotating electrical machines are widely used in automotive applications, particularly as a traction motor. Rotating electrical machines generally comprise a stator and a rotor arranged coaxially, the rotor being configured to rotate about an axis of rotation. The stator and rotor are arranged facing each other along the axis of rotation in a housing. The rotor is mounted on a rotor shaft which extends from the housing to mechanically interact with a pulley or gear to facilitate torque transfer. In one known configuration, the stator is supported by a bracket located in the housing. In this case, the rotor is arranged within a cavity of the stator. In addition, a gap is maintained between the outer periphery of the stator and the inner periphery of the bracket.Such a gap is particularly necessary in liquid-cooled rotating electrical machines, where a coolant circulates through this gap. This gap functions as a channel for the distribution of a coolant, such as oil, to cool the stator.

[0004] In the conventional rotating electrical machine having the configuration described above, it is important to maintain the gap uniform along the entire length of the stator. In other words, the width of the gap, or the distance between the outer periphery of the stator and the inner periphery of the support, should preferably remain uniform throughout the lifetime of the rotating electrical machine. The stator is supported at one end and cantilevered at the other. A cantilever effect is induced at the unsupported end of the stator, which causes deformation due to the weight of the stator. Such deflection can also occur upon exposure to vibration. This adversely affects the gap maintained between the stator and the support. Such deflection occurs particularly in the radial direction relative to the rotor rotational axis, thereby compromising the structural integrity of the channels.In particular, the circulation of the coolant through the channels is hindered. The stator windings are therefore not cooled in the intended manner. In particular, adequate circulation of the coolant is not achieved, which reduces the performance of the machine. rotating electric machine. Generally speaking, it can be said that due to the stator overhang effect and the deflection caused by the stator's weight, the structural and operational integrity of the rotating electric machine are compromised. In addition, stator deflection can lead to inefficient magnetic field interference between the stator and rotor. A rotating electric machine of this configuration therefore tends to operate poorly and inefficiently.

[0005] Therefore, the technical problem to be solved by the present object is to ensure that the gap between the housing and the stator is uniform and maintained regardless of factors such as vibration exposure and stator weight. Summary of the invention

[0006] The present object aims to solve the above-mentioned technical problem in conventional rotating electrical machines. The present object finds a particularly advantageous application in rotating electrical machines such as alternators, alternator starters, or even reversible machines or electric motors. A reversible machine is a rotating electrical machine which can operate reversibly, on the one hand as an electric generator in alternator function, and on the other hand as an electric motor, for example to start the thermal engine of a motor vehicle. The rotating electrical machine described here can also be used as a traction motor for hybrid or electric vehicles.

[0007] The present subject matter relates to a rotating electrical machine comprising: a rotor rotatable about an axis of rotation; a stator, in coaxial arrangement with the rotor, comprising a stator core and a winding; a housing comprising a chamber defined by a closed end at one end and an open end at another end, the chamber at least substantially receiving the rotor and the stator, wherein an inner surface of the housing and an outer surface of the stator core form an axially extending annular space therebetween; a support device at least partly disposed between the stator core and the housing, said support device at least partly covering the annular space and adapted to at least limit radial displacement of the stator core relative to the axis of rotation. As a result, radial displacement or deflection of the stator is limited. The integrity of the annular space is maintained.In other words, the annular gap defines a radial width between the outer surface of the stator core and the inner diameter of the housing, and this radial width is kept uniform along the entire length of the stator.

[0008] According to one aspect of the present subject matter, the support device comprises a lower surface facing the closed end of the housing and resting on a first recess formed on the interior surface of the housing, the first recess being an undercut formed radially outward from the axis of rotation. The support device is limited in its axial movement, particularly towards the closed end. The support device is thus assembled. The support device may be assembled in an interference fit between the inner surface of the housing and the outer surface of the stator core. The support device may also be secured by means of fasteners.

[0009] According to an example of the present subject matter, the support device comprises at least one channel that is at least partially formed and extends in an axial direction parallel to the axis of rotation. The at least one channel is aligned with the annular space so as to ensure adequate and uninterrupted flow of the coolant in the annular space. The support device thus has the additional function of maintaining the flow of the coolant while eliminating radial displacement of the stator.

[0010] According to an example of the present subject matter, the support device defines at least one flange that extends axially from the bottom surface of the support device. The at least one flange mechanically reinforces the structural integrity of the support device. The aforementioned advantage is particularly applicable when a width of the support device is small, the width being defined by the distance between the top surface and the bottom surface of the support device is small.

[0011] According to one aspect of the present subject matter, each of the at least one flange is disposed in a second recess formed on the interior surface of the housing, the second recess being an undercut formed radially outward of the axis of rotation. Accordingly, the at least one flange may facilitate indexing when assembling the support device to the housing of the rotating electrical machine.

[0012] According to one aspect of the present subject matter, the first recess is formed further in the radial direction from the axis of rotation than the second recess. Therefore, when assembled, the lower surface rests on the first recess while the at least one flange is within the second recess.

[0013] According to an example of the present subject matter, the at least one channel is at least partially formed on an inner face of the support device. An outer side of the support device is in contact with the inner surface of the housing and the inner side is in contact with the outer surface of the stator core to stop radial displacement of the stator.

[0014] According to another example of the present subject matter, the at least one flange is formed proximate the inner face and each of the at least one channel is formed along one of the at least one flange, wherein the at least one channel extends in the axial direction. This orientation of the at least one channel aligns it with the annular space, thereby facilitating the flow of coolant through the support device.

[0015] According to another example, the stator core comprises corresponding partial channels that correspond to the at least one channel formed on the support device, said at least one channel and the corresponding partial channels forming a conduit configured for the circulation of the cooling fluid. In other words, the conduit for circulation of the cooling fluid is partially formed on the support device and partially formed on the stator core. Thus, when assembling the support device to the rotating electrical machine, the at least one channel and the corresponding partial channels are aligned together to form the conduit through which the cooling fluid can circulate.

[0016] According to yet another example, the at least one channel forms a conduit in the support device and the conduit is oriented in the axial direction. In other words, the conduit is entirely formed in the support device to allow the cooling fluid to flow.

[0017] In one example of the present subject matter, the support device is formed from an electrically insulating material. Brief description of the drawings

[0018] The features, aspects and advantages of the present invention will be better understood in light of the following description and the accompanying figures. The description refers to the accompanying drawings, in which:

[0019] [Fig.l] illustrates a sectional view of a rotating electrical machine, configured in accordance with the present subject matter; and

[0020] [Fig.2] illustrates a zoomed perspective view of the rotating electric machine shown in [Fig.l], configured in accordance with this subject;

[0021] [Fig.3] illustrates an exploded view of the rotating electric machine, configured in accordance with this subject;

[0022] [Fig.4A] illustrates a device for supporting the rotating electric machine, in accordance with the present subject;

[0023] [Fig.4B] illustrates another perspective view of the support device, in accordance with the present subject matter; and

[0024] [Fig.5] illustrates a zoomed perspective of the support device arranged between a stator and a housing of the rotating electric machine, configured in accordance with this subject.

[0025] The figures are not necessarily to scale and the size of certain parts may be exaggerated to more clearly illustrate the example presented. In addition, the drawings provide examples and / or examples conforming to the description, but the description is not limited to the examples and / or examples provided in the drawings. DETAILED DESCRIPTION

[0026] In the following description, reference is made to the accompanying drawings, which form an integral part of the invention, and in which are illustrated specific embodiments in which the invention may be embodied. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that the embodiments may be combined, or that other embodiments may be used, and that structural and logical modifications may be made without departing from the scope of the present invention. The following detailed description is therefore not to be construed in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.

[0027] [Fig.l] illustrates a sectional view of a rotating electrical machine 100, configured in accordance with the present subject matter. The present subject matter relates to a rotating electrical machine 100 which comprises a rotor (not shown), a stator 104, a housing 110 and a support device 112. The rotor is rotatable about an axis of rotation 116. The stator 104 is disposed coaxially with the rotor. The stator 104 comprises a core 106 and windings 108a, 108b. The housing 110 comprises a chamber 122 defined by a closed end 120 at one end and an open end 118 at another end. The chamber 122 at least substantially receives the rotor and the stator 104. The inner diameter of the housing and the outer surface of the stator form an annular space 114 which extends axially therebetween. The support device 112 is at least partially disposed between the stator core 106 and the housing 110.Furthermore, the support device 112 at least partially covers the annular space 114 and is adapted to at least limit the radial displacement of the stator core 106. Radial displacement refers to a displacement of the stator core 106 relative to the axis of rotation 116.

[0028] For the purposes of this subject:

[0029] The terms "axially" or "axial direction" mean "a direction parallel to the axis of rotation 116 of the rotor",

[0030] "radial" or "radially" means "in a plane perpendicular to the axis of rotation 116 of the rotor and along a straight line intersecting this axis of rotation 116",

[0031] The term "annular space" of the annular space 114 means "a space which at least partially circumvents the outer surface of the stator core or at least partially the inner surface of the housing."

[0032] The stator core 106 extends lengthwise along the axial direction. One end of the stator core 106, along the axial direction, is mounted (thus supported) on the housing 110 by fasteners, and the other end is supported by the support device 112. Thus, the stator core 104 is supported at both ends. The annular space 114 is thus maintained uniformly in the axial direction.

[0033] According to an example of the present subject matter, the stator core 106 is a laminated stator core 106 that includes a plurality of stacked laminations (not shown), although it is possible for the stator core 106 not to be laminated. The stator core 106, in this example, includes a ferromagnetic material such as steel, although the use of one or more electrically conductive materials is permissible without departing from the scope of the present subject matter. Preferably, the stator core 106 includes a plurality of arcuately spaced and generally radially extending teeth. More particularly, each of the teeth includes a generally circumferentially extending yoke, a generally radial arm extending from the yoke, and a ring extending generally circumferentially of the arm.The winding 108a, 108b is an electrically conductive wire wound multiple times around each tooth to form a plurality of turns or loops. The electrically conductive wire is preferably formed of copper or aluminum, although one or more electrically conductive materials or a combination thereof may be used within the scope of this subject matter. Further, the wire may be coated or uncoated. The wiring is wound around the teeth in a particular manner depending on the configuration and desired performance characteristics of the rotating electrical machine 100. The windings 108, 108b may also be formed of insulated copper bars (or aluminum, or a combination of both) in the form of so-called pins, U-pins, or hairpins.

[0034] In an example where the rotating electric machine 100 is used for the propulsion of a motor vehicle, the rotating electric machine 100 can operate in motor mode in which an electric current passes through the winding 108a, 108b, and allows the creation of a magnetic field which causes rotation of the rotor. When the rotating electric machine 100 operates in generator mode, the rotational movement of the rotor allows the creation of a magnetic field in the stator 104, this magnetic field being transformed into an electric current which passes through the winding 108a, 108b of the stator 104 to provide electrical power to various equipment in the motor vehicle.

[0035] According to one aspect of the present subject matter, the stator core 106 is disposed in the chamber 122 through the open end 118 of the housing 110. The stator core 106 is rigidly mounted within the housing 110. The rotor is disposed in a central cavity of the stator core 106. The rotor is capable of rotating relative to the stator 104, and more particularly of rotating about the axis of rotation 116. The rotor is carried by a shaft (not shown) and can rotate about the axis of rotation 116 in motor mode and / or in generator mode of the rotating electrical machine 100. Furthermore, the support device 112 is arranged axially towards the open end 118 of the housing 110, in a direction along the axis of rotation 116, so that it is at least partly arranged axially between the stator core 104 and the housing 110. The support device 112 is arranged so as to at least partly cover the annular space 114. In other words, the support device 112 extends at least partly axially into the annular space 114. Accordingly, during operation of the rotating electrical machine 100, the stator 104 does not move radially.Furthermore, the rotation axis 116 does not deviate from its intended initial position, which ensures that the stator 104 does not move radially and adversely affect the rotation of the rotor. Structural and operational integrity is therefore maintained.

[0036] [Fig. 2] illustrates an enlarged view of the rotating electrical machine 100 also illustrated in [Fig. 1]. According to the present subject matter, the support device 112 is arranged such that it is at least partially disposed between the stator core 106 and the housing 110. More particularly, the support device 112 is arranged such that at least a portion extends axially into the annular space 114. The annular space 114 extends substantially along the length of the stator core 106. By means of the support device 112, the annular space 114 is maintained uniformly along the length of the stator core 106.

[0037] According to one aspect of the present subject matter, the support device 112 comprises a lower surface. The lower surface faces the closed end 120 of the housing 110. When the support device 112 is disposed between the stator core 106 and the housing 110, the lower surface rests on a first recess 204 formed on the inner surface of the housing. The first recess 204 is an undercut formed on the inner surface of the housing. The aforementioned undercut is formed radially outward of the rotational axis 116. In the example illustrated in the figures, the first recess 204 is continuously formed on the inner surface of the housing.

[0038] According to an example of the present subject matter, the support device 112 comprises at least one channel 202, each being at least partially formed. The at least one channel 202 extends axially, more precisely towards the closed end 120 of the housing 110. The at least one channel 202 is formed as a conduit for an uninterrupted flow of the cooling fluid into the annular space 114. Accordingly, the cooling fluid can enter or exit the annular space 114. The aforementioned configuration is particularly advantageous for rotating electrical machines 100 liquid-cooled. In such rotating electrical machines 100, the annular space 114 allows the flow of the cooling fluid and directs said cooling fluid toward the windings 108a, 108b of the stator 104. In a non-limiting example, the cooling fluid is allowed to radially enter the housing 110 via an orifice (not shown), formed on the housing 110, and to flow into the annular space 114. The cooling fluid, for example, cooling oil, water, etc., is then dispersed to cool the windings 108a, 108b of the stator 104. The annular space 114 has a radial width between the outer surface of the stator core and the inner diameter of the housing. The aforementioned radial width of the annular space 114 is uniform over the entire length of the stator 104 thanks to the support device 112.A constant flow of coolant is thus maintained during operation of the rotating electrical machine 100. Thus, the support device 112 has a dual function - first, to maintain the radial width of the annular space 114 along the length of the stator core 106; and second, to maintain an uninterrupted flow of coolant in the annular space 114 during operation of the rotating electrical machine 100.

[0039] [Fig.3] illustrates an exploded view of the rotating electric machine 100, in accordance with an example of the present subject matter. [Fig. 4A] illustrates the support device 112 in accordance with an example of the present subject matter. [Fig. 4B] illustrates another perspective view of the support device 112 shown in [Fig. 4A]. For the sake of brevity, the following description relates to [Fig. 3], 4A and 4B in tandem.

[0040] The support device 112, as explained in the preceding description, is disposed at least in part between the stator core 106 and the housing 110. The support device 112 contours the outer surface 304 of the stator core 104 and is disposed at least in part in the annular space 114 formed between the inner surface 300 of the housing and the outer surface 304 of the stator core. In the example of [Fig. 3], the stator core 106 has a substantially star-shaped profile. Accordingly, in this example, the inner surface of the housing 300 is formed with a complementary star-shaped profile to accommodate the stator core 106. Furthermore, when the stator 104 is placed in a chamber 122 of the housing 110, the annular space 114 is formed with a star-shaped profile.Therefore, in the illustrated example, the support device 112 is also formed in a substantially star-shaped profile so as to bypass the stator core 106 and to be disposed at least partly in the annular space 114. The aforementioned example is a non-limiting configuration of the rotating electrical machine 100. The stator core 106, in particular the outer surface of the stator core 304, and consequently the inner surface of the housing 300, may alternatively have an at least substantially star-shaped profile. circular. Furthermore, in the preceding example, the annular space 114 is formed with at least one substantially circular profile. Accordingly, the support device 112 has a substantially circular profile.

[0041] [Fig. 4A] shows an upper surface 400, an inner side 404 and an outer side 406 of the support device 112, [Fig. 4B] illustrates a lower surface 402. The lower surface 402 is seated on a first recess 204 formed on the inner surface of the housing 300 (illustrated in [Fig. 2]). The support device 112 is oriented so that the lower surface 402 is oriented towards the closed end 120 of the housing 110. When the support device 112 is placed in the annular space 114, the inner side 404 is in contact with the outer surface 304 of the stator core and the outer side 406 is in contact with the inner surface 300 of the housing. The outer side 404 is specifically configured to rest on the first recess 204.In one example, the support device 112 is disposed in the annular space 114 in an interference fit between the outer surface of the stator core 304 and the inner surface of the housing 300. In yet another example (not shown), the support device 112 is secured to the housing 110, particularly to the first recess 204, by means of fasteners, such as screws, rivets, etc., inserted into holes formed axially on the support device 112. Thus, the support device 112 does not loosen during its use in the rotating electrical machine 100.

[0042] According to the examples shown, in particular in [Fig.4A] and 4B, there are four channels 202, each adapted to allow circulation of the cooling fluid in the annular space 114. The four channels 202 are axially aligned towards the closed end 120. Each of the four channels 202 is partially formed and adapted to allow circulation of the cooling fluid.

[0043]

[0044] Accordingly, the stator core 106 includes corresponding partial channels 500, with reference to [Fig. 5] illustrating a zoomed-in view of the support device 112 disposed between the stator core 106 and the housing 110, which, upon assembly, aligns with the channels 202 of the support device 112 to form a conduit through which the coolant is allowed to flow. In other words, the conduit is partially formed on the support device 112 and partially formed on the stator core 106. For the purposes of this disclosure, "assembly" means "disposing the support device 112 in the annular space 114 and the lower surface 402 in contact with the first recess 204". Alternatively, the at least one channel 202 is formed as a conduit through the support device 112, thereby allowing the cooling fluid to circulate through said device 112. Such a conduit of the aforementioned other example is oriented in an axial direction to align with the annular space 114.

[0045] According to an example of the present subject matter, the support device 112 defines at least one flange 200 (also illustrated in [Fig. 2]) formed from the bottom surface 402. The at least one flange 200 extends in an axial direction toward the closed end 120 of the housing 110. The at least one flange 200 is formed at least partially around the circumference of the bottom surface 402. The at least one flange 200 is formed proximate the inner side 404 of the support device 112. Each of the at least one channel 202 is formed along one of the at least one flange 200, each channel 202 thereby extending in the axial direction. Furthermore, such an orientation also ensures that the conduit formed by the at least one channel 202 is aligned with the annular space 114 so as to facilitate the flow of the coolant.Furthermore, when assembling the support device 112, the at least one flange 200 is disposed in a second recess 206 (shown in [Fig. 2] and 3) formed on the inner surface of the housing 300. The second recess 206 is an undercut formed on the surface of the housing 300. The undercut is formed radially outward of the rotation axis 116. The first recess 204 is formed further in the radial direction of the rotation axis 116 than the second recess 206. In other words, the first recess 204 has an undercut whose depth is greater than that of the second recess 206. The first recess 204 of the examples shown in [Fig. 2] and 3 is formed continuously in a loop on the inner surface of the housing 300. .

[0046] According to an example of the present subject, each of the at least one flange 200 is provided with a channel 202. These channels 202 may be partially formed so as to form a conduit with the corresponding partial channels 500 of the stator core 106. Alternatively, these channels 202 form a conduit through the support device 112 through which the cooling fluid can circulate.

[0047] In the example where the support device 112 is substantially circular in shape, these flanges 200, by virtue of their axial extension, facilitate indexing during assembly. Furthermore, in this document, the term "indexing" refers to "the error-free alignment of the support device 112 when placed in the annular space 114", a concept also known as "poka-yoke". When assembling the support device 112 to the rotating electrical machine 100, the flanges 200 are disposed in the second recess 206 and an uninterrupted means of circulation of the coolant is provided by the channels 202.

[0048] Without limitation, the support device 112, in accordance with the present subject matter, may be formed of an electrically insulating material.

[0049] The present subject matter relates to the application of the rotating electric machine to automobiles, but it is understood that the application may extend to various other industries and may be used in fans, blowers, machine tools, turbines, pumps, compressors, rolling mills, movers, paper mills, etc.

[0050] Various modifications to the disclosed embodiments, as well as other embodiments of the subject matter, will become apparent to those skilled in the art upon reference to the description of the subject matter. It is therefore contemplated that such modifications may be made without departing from the scope of the present subject matter.

Claims

Claims

1. A rotary electrical machine (100) comprising a rotor rotatable about an axis of rotation (116); a stator (104), coaxially disposed with the rotor, comprising a stator core (106) and windings (108a; 108b); a housing (110) comprising a chamber (122) defined by a closed end (120) at one end and an open end (118) at another end, the chamber (122) at least substantially receiving the rotor and the stator (104), wherein an inner surface of the housing (300) and an outer surface of the stator core (304) form an annular space (114) extending axially therebetween; a support device (112) arranged at least partly between the stator core (106) and the housing (110), said support device (112) at least partly covering the annular space (114) and adapted to at least limit the radial displacement of the stator core (106) relative to the axis of rotation (116).

2. A rotating electrical machine (100) according to claim 1, wherein the support device (112) comprises a lower surface (402) facing the closed end (120) of the housing (110) and resting on a first recess (204) formed on the inner surface of the housing (300), wherein the first recess (204) is an undercut formed radially outwardly from the axis of rotation (116).

3. A rotating electrical machine (100) according to claim 2, wherein the support device (112) comprises at least one channel (202) which is at least partially formed and which extends in an axial direction parallel to the axis of rotation (116).

4. A rotating electrical machine (100) according to claim 3, wherein the support device (112) defines at least one flange (200) which extends axially from the lower surface (402) of the support device (112).

5. The rotating electrical machine (100) of claim 4, wherein each of the at least one flange (200) is disposed in a second recess (206) formed on the inner surface of the housing (300), the second recess (206) being an undercut formed radially outward from the axis of rotation (116).

6. A rotating electrical machine (100) according to any one of claims 2 to 5, wherein the first recess (204) is formed further in the radial direction from the rotation axis (116) than the second recess (206).

7. A rotating electrical machine (100) according to any preceding claim, wherein the at least one channel (202) is at least partially formed on an inner face (404) of the support device (112).

8. A rotating electrical machine (100) according to one of claims 3 to 6, wherein at least one flange (200) is formed near the inner side (404) and each of the at least one channel (202) is formed along one of the at least one flange (200), wherein the at least one channel (202) extends in the axial direction.

9. A rotating electrical machine (100) according to claim 8, wherein the stator core (106) comprises corresponding partial channels (500) which correspond to the at least one channel (202) formed on the support device (112), said at least one channel (202) and the corresponding partial channels (500) forming a conduit configured for the flow of the cooling fluid.

10. A rotating electrical machine (100) according to any one of claims 2 to 8, wherein the at least one channel (202) forms a conduit in the support device (112) and the conduit is oriented in the axial direction.

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