Cover for an electric drivetrain system

Abstract

The present subject matter relates to a cover (100) for an electric drivetrain system for automobile applications. The cover (100) includes a flat surface (5) and a curved surface (10). At least a part of the flat surface (5) is in a reference plane (15). At least part of the curved surface (10) is away from the reference plane (15) creating at least two portions, a first portion (11 ) and a second portion (12). The second portion (12) is formed inside of the first portion (11 ). Further, with respect to the reference plane (15), one of the first portion (11 ) or the second portion (12) is concave and the other of the first portion (11 ) or the second portion (12) is convex, intended for noise mitigation and at least 6% of part of the curved surface (10) is away from the reference plane (15).

Description

[0001] Cover for an Electric drivetrain system

[0002] Field of the invention

[0003] The present subject matter relates to an electric drivetrain system, particularly to a cover for an electric drivetrain system for automobile applications.

[0004] Background of the invention

[0005] An electric vehicle or a hybrid vehicle includes equipments like a motor unit for propulsion, a reducer coupled with the motor unit to transfer a torque to the wheels of the vehicle, a power electronics system connected with the motor unit for supplying an electric current to the motor unit from a battery. The power electronics system includes an inverter for converting the direct current of the battery into alternating current for the motor unit. The said motor unit, power electronics system, reducer and the like together constitutes the electric drivetrain system. The said equipments of the electric drivetrain system is arranged with a specific positional relationship in a housing space available in the automobile. In a known manner, the said equipments of the electric drivetrain system may have a single integrated housing accommodating the said equipments of the electric drivetrain system or may have an individual housing for each equipment and a cover assembly for enclosing the said equipments with the housing. In general, the cover is a thin shaped structure, which is prone to noise, vibration and harshness generated. The first fundamental or Natural frequency of this component is called the Pumping or loudspeaker or membrane mode. The phenomenon of excitation of the pumping or loudspeaker or membrane mode by the vibration source in the vicinity of the natural frequency of the cover acts like a monopole source that radiates sound very effectively during the operation of the automobile.

[0006] Considering the power electronics system comprising the inverter of the electric drivetrain system of an automobile as an example known in the art. The inverter has a cover provided with cambered surfaces that serves to dampen the vibratory excitation of the cover, consequently, reducing the noise generated by the cover, during the operation of the automobile.

[0007] However, the said power electronics system of the electric drivetrain system must be installed in the housing space available along with the said equipments of the electric drivetrain system.

[0008] There is therefore a need to solve the technical problem associated with the assembly explained above from a space constraint standpoint along with the consideration of Noise Vibration and Harshness.

[0009] Summary of the invention

[0010] It is accordingly an object of the present invention to provide an assembly, which overcomes the above mentioned and other disadvantages of the known arrangements and provide a cover for an electric drivetrain system.

[0011] The present invention relates to a cover for an electric drivetrain system comprising a flat surface and a curved surface, at least a part of the flat surface is in a reference plane, at least part of the curved surface is away from the reference plane creating at least two portions, a first portion and a second portion, the said second portion is formed inside of the first portion, characterized in that with respect to the reference plane, one of the first portion or the second portion is concave and the other of the first portion or the second portion is convex.

[0012] The invention has the advantage of providing a cover with high rigidity without taking up too much space within the electric vehicle. The axial extent of the electric drivetrain system is reduced.

[0013] According to an aspect of the invention, as intended for noise mitigation, at least 6% of part of the curved surface is away from the reference plane. Therefore, by virtue of which, the overall transverse height of the cover for accommodating components could be controlled such that the problem associated with the space constraints will be improved along with the advantage of having noise mitigation.

[0014] According to an aspect of the invention, as intended for noise mitigation, the curved surface corresponds to minimum 6% of part of the cover, for example corresponds to minimum 20 % of part of the cover. Consequently, the flat surface corresponds to maximum 94% of part of the cover.

[0015] According to an aspect of the invention, the first portion is provided with a first radius of curvature R1 1 and the second portion is provided with a second radius of curvature R12.

[0016] According to an aspect of the invention, with respect to the reference plane, the first portion or the second portion is elliptical.

[0017] According to another aspect of the invention, with respect to the reference plane, the first portion or the second portion is spherical. By virtue of which the cover with the first portion and the second portion could be manufactured by a simple stamping process.

[0018] According to another aspect of the invention, with respect to the reference plane, the first portion or the second portion is concentric. Consequently, which reduces the space occupied by the cover.

[0019] According to another aspect of the invention, with respect to the reference plane, the first portion is concave and the second portion is convex.

[0020] According to another aspect of the invention, with respect to the reference plane, the first portion is convex and the second portion is concave.

[0021] According to another aspect of the invention, a first boundary of the first portion in point of curvature of the first portion is circular and having a first diameter D1 1 and a second boundary of the second portion in point of curvature of the second portion is circular and having a second diameter According to another aspect of the invention, the second diameter D12 is between 0.1 times and 0.9 times the first diameter D11 .

[0022] According to another aspect of the invention, the second diameter D12 is higher the first diameter D1 1 .

[0023] According to another aspect of the invention, a first height H1 1 is the distance between the first boundary and the second boundary in a direction normal to the reference plane and a second height H12 is the distance in a direction normal to the reference plane, between the second boundary and a centre of curvature of the second portion.

[0024] According to another aspect of the invention, a first height H1 1 is the distance between the first boundary and the second boundary in a direction normal to the reference plane, and the first height H1 1 is given by

[0025] According to another aspect of the invention, the second height H12 is the distance in a direction normal to the reference plane, between the second boundary and a centre of curvature of the second portion, and the first height H11 is higher than the second height H12. By this way, the axial extent of the electric drivetrain system is reduced.

[0026] According to another aspect of the invention, the second height H12 is the distance in a direction normal to the reference plane, between the second boundary and a centre of curvature of the second portion, and the first height H11 is lower than the second height H12. By this way, the axial extent of the electric drivetrain system is reduced.

[0027] According to another aspect of the invention, a first ratio of the first diameter D11 to the first radius of the curvature R1 1 is between 0.06 and 2, and a second ratio of the second diameter D12 to the second radius of curvature R12 is between 0.03 and 2. Accordingly, by adjusting the first radius of curvature, the second radius of curvature, the first diameter and the second diameter, the overall transverse height of the cover could be controlled by considering packing constraint into account along with the advantage of improving vibroacoustic noise.

[0028] According to another aspect of the invention, the first boundary of the first portion in point of curvature of the first portion is elongated circular profile / elliptical and the second boundary of the second portion in point of curvature of the second portion is elongated circular profile / elliptical.

[0029] According to another aspect of the invention, the first boundary of the first portion in point of curvature of the first portion is with polygonal ends with plurality of external diameters and the second boundary of the second portion in point of curvature of the second portion is with polygonal ends with plurality of external diameters.

[0030] According to another aspect of the invention, the cover comprises plurality of the curved surfaces having the first portion and the second portion.

[0031] According to another aspect of the invention, the present subject matter relates to an electric drivetrain system for use in an automobile application comprising an equipment, the equipment being an inverter, a DC-DC converter, a motor or a reducer comprising a housing and the cover in accordance with the present arrangement and at least part of the flat surface of the cover is being attached to the housing.

[0032] Brief description of drawings

[0033] The features, aspects and advantages of the present invention can be better understood with reference to the following description and figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the arrangement. Moreover, in the figures, like reference numerals designate corresponding parts. In the drawings: [Figure 1A] illustrates a perspective view of an embodiment of a cover for an electric drivetrain system configured in accordance with the present subject matter.

[0034] [Figure 1 B] illustrates a cross sectional side view of an embodiment of a cover for an electric drivetrain system configured in accordance with the present subject matter.

[0035] [Figure 2A] illustrates a perspective view of another embodiment of a cover for an electric drivetrain system configured in accordance with the present subject matter.

[0036] [Figure 2B] illustrates a cross sectional side view of another embodiment of a cover for an electric drivetrain system configured in accordance with the present subject matter.

[0037] [Figure 3] illustrates a cross sectional side view of an equipment, the equipment being an inverter comprising a cover for an electric drivetrain system configured in accordance with the present subject matter.

[0038] Detailed description

[0039] [Figure 1 A] illustrates a perspective view of an embodiment of a cover for an electric drivetrain system configured in accordance with the present subject matter configured in accordance with the present subject matter. [Figure 1 B] illustrates a cross sectional side view of the embodiment of the cover for an electric drive train system shown in [Figure 1 A] configured in accordance with the present subject matter. [Figure 2A] illustrates a perspective view of an embodiment of a cover for an electric drivetrain system configured in accordance with the present subject matter and [Figure 2B] illustrates a cross sectional side view of the embodiment of the cover for an electric drive train system shown in [Figure 2A] configured in accordance with the present subject matter. The description herein pertains to [Figure 1A], [Figure 1 B], [Figure2A] and, [Figure2B] in tandem for the sake of brevity.

[0040] The present subject matter relates to a cover 100 for an electric drivetrain system. The said cover 100 includes a flat surface 5 and a curved surface 10, at least a part of the flat surface 5 is in a reference plane 15 and at least part of the curved surface 10 is away from the reference plane 15. The curved surface 10 away from the reference plane 15 creating at least two portions, a first portion 1 1 and a second portion 12. The said second portion 12 is formed inside of the first portion 11. Further, with respect to the reference plane 15, one of the first portion 11 or the second portion 12 of the cover 100 is concave and the other of the first portion 1 1 or the second portion 12 is convex, intended for noise mitigation and at least 6% of part of the curved surface 10 is away from the reference plane 15.

[0041] In an embodiment as illustrated in [Figure 1 A], [Figure 1 B], [Figure2A] and, [Figure2B], the part of the flat surface 5 is in the reference plane 15. The curved surface 10 extending integrally from the flat surface 5 is away from the reference plane 15 in a direction normal to the reference plane 15. The curved surface 10 is configured by the first portion 1 1 and the second portion 12. The second portion 12 is formed inside of the first portion 1 1 . The first portion 1 1 of the curved surface 10 is provided with a first radius of curvature R11 and the second portion 12 of the curved surface 10 is provided with a second radius of curvature R12.

[0042] In an embodiment as illustrated in [Figure 1 A] and [Figure 1 B], the first portion 1 1 is concave and the second portion 12 is convex. In another embodiment as illustrated in [Figure2A] and [Figure2B], the first portion 1 1 is convex and the second portion 12 is concave.

[0043] With continued reference to the [Figure 1 A], [Figure 1 B], [Figure2A] and [Figure2B], the first portion 1 1 of the curved surface 10 extends integrally from the flat surface 5. The transition between the flat surface 5 and the first portion 1 1 creates a first boundary of the first portion 1 1 . The first boundary is in point of curvature of the first portion 1 1 . As shown in [Figure 1 A] and [Figure 2A] the first boundary is circular and having a first diameter D1 1 .

[0044] In addition from the [Figure 1 A], [Figure 1 B], [Figure2A] and, [Figure2B], the second portion 12 of the curved surface 10 extends integrally from the first portion 1 1 . The transition between the first portion 1 1 and the second portion 12 creates a second boundary of the second portion 12. The second boundary is in point of curvature of the second portion 12. In other words, intersection of the first portion 1 1 and the second portion 12 creates the second boundary. As shown in [Figure 1 A] and [Figure 2A] the second boundary is circular and having a second diameter D12. Preferably, the second diameter D12 is between 0.1 times and 0.9 times the first diameter D11. In other words, the ratio between the second diameter D12 and the first diameter D11 is between 0.1 and 0.9.

[0045] As shown in [Figure 2B], the second diameter D12 is higher than the first diameter D1 1 .

[0046] In a non-limiting manner, the first boundary is in the reference plane 5 and the second boundary is away from the reference plane 5. The first boundary is in the flat surface 5. The second boundary is disposed in the intersection between the first portion 1 1 and the second portion 12. It should be noted here that, the first portion 1 1 is delimited by the first boundary and the second boundary. In addition, with respect to the reference plane 15, the first portion 1 1 and the second portion 12 are disposed concentrically.

[0047] With continued reference to the [Figure 1 A], [Figure 1 B], [Figure2A] and [Figure2B], a height of the cover is defined in a direction normal to the reference plane 15. A first height H1 1 is defined as the distance between the first boundary and the second boundary in a direction normal to the reference plane 15. A second height H12 is defined as the distance in a direction normal to the reference plane 15, between the second boundary and a centre of curvature of the second portion 12. The first height H1 1 is given by Hll

[0048] Preferably, a first ratio of the first diameter D1 1 to the first radius of curvature R11 is between 0.06 and 2, and a second ratio of the second diameter D12 to the second radius of curvature R12 is between 0.03 and 2.

[0049] In a non-limiting example, the first portion 1 1 extends away from the reference plane 15 and the second portion 12 extends towards the reference plane 15 as illustrated in [Figure 1A], [Figure 1 B], [Figure2A] and [Figure2B],

[0050] In an embodiment, the first portion 1 1 and the second portion 12 are within the first height H11 .

[0051] As shown in [Figure 2B], the first height H1 1 is higher than the second height H12.

[0052] In an embodiment, the first portion 1 1 or the second portion 12 is elliptical. In another embodiment, the first portion 1 1 or the second portion 12 is spherical. In a non-limiting example, combination of the above embodiments is possible.

[0053] In an embodiment, the first portion 1 1 of the curved surface 10 extends integrally from the flat surface 5. The transition between the flat surface 5 and the first portion 1 1 creates a first boundary of the first portion 1 1 . The first boundary is in point of curvature of the first portion 1 1 and is an elongated circular profile or an elliptical.

[0054] In another embodiment, the second portion 12 of the curved surface 10 extends integrally from the first portion 11 . The transition between the first portion 1 1 and the second portion 12 creates a second boundary of the second portion 12. The second boundary is in point of curvature of the second portion 12. In other words, intersection of the first portion 1 1 and the second portion 12 creates the second boundary. The second boundary is in point of curvature of the second portion 12 and is an elongated circular profile or an elliptical.

[0055] In yet another embodiment, the first boundary of the first portion 11 in point of curvature of the first portion 1 1 is with polygonal ends with plurality of external diameters.

[0056] In yet another embodiment, the second boundary of the second portion 12 in point of curvature of the second portion 12 is with polygonal ends with plurality of external diameters. In a non-limiting example, combination of the above embodiments are possible.

[0057] In another embodiment, the cover 100 comprises plurality of the curved surfaces 10 having the first portion 11 and the second portion 12.

[0058] In yet another embodiment not shown, all the plurality of curved surfaces 10 of the cover 100 having the first portion 1 1 and the second portion 12 are within the same first height H1 1 .

[0059] The cover 100 for an electric drivetrain system in accordance with the present subject matter, as described above is specifically advantageous for use in an equipment of an electric drivetrain system for an automobile as illustrated in [Figure 3]. [Figure 3] illustrates a cross sectional side view of an inverter comprising a housing 101 and a cover 100 for an electric drivetrain system configured in accordance with the present subject matter. The part of the flat surface 5 is attached with the flat surface of the housing 101 by a bolt and nut or with an adhesive means. The housing 101 is configured to receive the components of the inverter. As illustrated in [Figure 3], the overall transverse height of the inverter is reduced by virtue of the curved surface 10 comprising the first portion 1 1 and the second portion 12 that is extended below the reference plane 15 of the cover 100, consequently creating a space above the cover 100 for integration of other components or machine. Such that the problem associated with the space constraints is improved. Accordingly, the inverter can be installed in the housing space available along with the equipments like DC-DC converter, a motor, a reducer of the electric drivetrain system.

[0060] In a non-limiting example, the equipment being, a DC-DC converter comprising a housing and the cover 100 for an electric drivetrain system configured in accordance with the present subject matter as described above. The housing is configured to receive the components of the DC-DC converter.

[0061] In another example, the equipment being a motor or a reducer that is assembled within a housing and the cover 100 for an electric drivetrain system configured in accordance with the present subject matter as described above.

Claims

Claims

1. A cover (100) for an electric drivetrain system comprising: a flat surface (5) and a curved surface (10); at least a part of the flat surface (5) is in a reference plane (15); at least part of the curved surface (10) is away from the reference plane (15) creating at least two portions, a first portion (11 ) and a second portion (12), the said second portion (12) is formed inside of the first portion (1 1 ), characterized in that with respect to the reference plane (15) one of the first portion (1 1 ) or the second portion (12) is concave and the other of the first portion (1 1 ) or the second portion (12) is convex.

2. The cover (100) according to claim 1 , wherein the first portion (1 1 ) is provided with a first radius of curvature R1 1 and the second portion (12) is provided with a second radius of curvature R12.

3. The cover (100) according to claim 2, wherein with respect to the reference plane (15), the first portion (1 1 ) or the second portion (12) is elliptical.

4. The cover (100) according to claim 2, wherein with respect to the reference plane (15), the first portion (1 1 ) or the second portion (12) is spherical.

5. The cover (100) according to one of the claims 1 to 4, wherein with respect to the reference plane (15), the first portion (1 1 ) and the second portion (12) are concentric.

6. The cover (100) according to one of the claims 1 to 5, wherein with respect to the reference plane (15), the first portion (1 1 ) is concave and the second portion (12) is convex.

7. The cover (100) according to one of the claims 1 to 5, wherein with respect to the reference plane (15), the first portion (11 ) is convex and the second portion (12) is concave.

8. The cover (100) according to the claim 4, wherein a first boundary of the first portion (1 1 ) in point of curvature of the first portion (1 1 ) is circular and having a first diameter D1 1 and a second boundary of the second portion (12) in point of curvature of the second portion (12) is circular and having a second diameter D12.

9. The cover (100) according to the preceding claim, wherein the second diameter D12 is between 0.1 times and 0.9 times the first diameter D1 1 .

10. The cover (100) according to the claim 8 or 9, wherein a first height H1 1 is the distance between the first boundary and the second boundary in a direction normal to the reference plane (15), wherein the first height H1 1 is given by[Claim 1 1 ] The cover (100) according to the claim 8 or 9, wherein a first height H1 1 is the distance between the first boundary and the second boundary in a direction normal to the reference plane (15), and a second height H12 is the distance in a direction normal to the reference plane (15) between the second boundary and a centre of curvature of the second portion (12), wherein the first height H11 is higher than the second height H12.

12. The cover (100) according to one of the claims 8 to 11 , wherein a first ratio of the first diameter D1 1 to the first radius of curvature R11 is between 0.06 and 2, and a second ratio of the second diameter D12 to the second radius of curvature R12 is between 0.03 and 2.

13. The cover (100) according to the claim 3, wherein the first boundary of the first portion (1 1 ) in point of curvature of the first portion (1 1 ) is elongated circular prof ile / elliptical and the second boundary of the second portion (12) in point of curvature of the second portion (12) is elongated circular prof ile / elliptical.

14. The cover (100) according to the claim 1 , wherein the first boundary of the first portion (1 1 ) in point of curvature of the first portion (1 1 ) is with polygonal ends with plurality of external diameters and the second boundary of the second portion (12) in point of curvature of the second portion (12) is with polygonal ends with plurality of external diameters.

15. The cover (100) according to one of the claims 1 to 14, wherein the cover (100) comprises plurality of the curved surfaces (10) having the first portion (1 1 ) and the second portion (12).

16. An electric drivetrain system for use in an automobile application comprising an equipment, the equipment being an inverter, a DC-DC converter, a motor or a reducer comprising a housing and the cover (100) as claimed in any one of the claims 1 to 15, at least part of the flat surface (5) of the cover (100) is being attached to the housing.

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