Electric drive unit having cover system for interacting with high voltage interlock circuit

Abstract

A high-voltage interlock (HVIL) circuit for an electric drive unit in a vehicle includes a frame, configured to couple to a housing of the electric drive unit, having a first connector receptacle that is configured to releasably and electrically couple with a first portion of a busbar; a second connector receptacle that is configured to releasably and electrically couple with a second portion of the busbar; a disconnect jumper assembly, configured to couple to a removable cover assembly of the housing, including: the busbar, having the first portion of the busbar configured to releasably and electrically connect with the first connector receptacle; the second portion of the busbar configured to releasably and electrically connect with the second connector receptacle.

Description

ELECTRIC DRIVE UNIT HAVING COVER SYSTEM FOR INTERACTING WITHHIGH VOLTAGE INTERLOCK CIRCUITFIELD

[0001] The present disclosure relates to an electric drive unit having a cover system for interacting with a high-voltage interlock circuit.BACKGROUND

[0002] This section provides background information related to the present disclosure which is not necessarily prior art.

[0003] There is increasing level of interest on the part of vehicle manufacturers to incorporate electric motors into the vehicle drivetrain. As such electric motors are typically provided with relatively high voltage and current electrical power, there is a desire to interrupt the supply of electrical power to an electric motor in situations where the high-power electric leads of the electric motor are exposed. A high-voltage interlock (HVIL) circuit is typically employed in such situations to interrupt the supply of electrical power to the electric leads of the electric motor when the electric leads are exposed. Such high-voltage interlock circuits typically employ discrete switches or sensors to sense the presence of a cover and to interact with circuitry and / or a relay of the high-voltage interlock circuit to interrupt the supply of electrical power when the presence of the cover Is not detected. An example of such a system is described in commonly assigned International (PCT) Patent Application No. PCT / IB2021 / 052581 filed March 29, 2021 , the disclosure of which is incorporated by reference as if fully set forth in detail herein.

[0004] While such configurations are suitable for their intended use, the use of discrete switches and / or sensors increases part count, cost and labor.Accordingly, there remains a need in the art for a high-voltage interlock circuit that does not employ discrete switches or sensors.SUMMARY in one implementation, a high-voltage interlock (HVIL) circuit for an electric drive unit in a vehicle includes a frame, configured to couple to a housing of the electric drive unit, having a first connector receptacle that is configured to releasably and electrically couple with a first portion of a busbar; a second connector receptacle that is configured to releasably and electrically couple with a second portion of the busbar: a disconnect jumper assembly, configured to couple to a removable cover assembly of the housing, including: the busbar, having the first portion of the busbar configured to releasably and electrically connect with the first connector receptacle; the second portion of the busbar configured to releasably and electrically connect with the second connector receptacle, wherein the HVIL is in a conductive mode while the first portion of the busbar is electrically coupled to the first connector receptacle and the second portion of the busbar is electrically coupled to the second connector receptacle; and the HVIL is in a non- conductive mode while the first sensing connector and the second sensing connector are separated from the busbar.In another implementation, an HVIL circuit for an electric drive unit in a vehicle includes a frame, configured to couple to a housing of the electric drive unit, having a planar mounting surface and a central spine with planar tangs, having: a first connector receptacle held between the planar tangs that is configured to releasably and electrically couple with a first portion of a busbar; asecond connector receptacle held between the planar tangs that is configured to releasably and electrically couple with a second portion of the busbar; a disconnect jumper assembly, configured to couple to a removable cover assembly of the housing, including: the busbar, having the first portion of the busbar configured to releasably and electrically connect with the first connector receptacle; the second portion of the busbar configured to releasably and electrically connect with the second connector receptacle, wherein the HVIL is in a conductive mode while the first portion of the busbar is electrically coupled to the first connector receptacle and the second portion of the busbar is electrically coupled to the second connector receptacle; and the HVIL is in a non-conductive mode while the first sensing connector and the second sensing connector are separated from the busbar.DRAWINGS

[0005] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0006] Figure 1 is a cross-sectional view of a portion of an implementation of an electric drive unit constructed in accordance with the teachings of the present disclosure;

[0007] Figure 2 is a perspective view depicting an implementation of a cover connector assembly used in an electric drive unit;

[0008] Figures 3a-3c are perspective views depicting an implementation of a portion of a cover connector assembly used in an electric drive unit;

[0009] Figure 4 is a perspective view depicting a portion of an implementation of a cover connector assembly used in an electric drive unit;

[0010] Figures 5a-5c are perspective views depicting a portion of an implementation of a cover connector assembly used in an electric drive unit; and

[0011] Figure 6 is a perspective view depicting an implementation of a cover connector assembly used in an electric drive unit.

[0012] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.DETAILED DESCRIPTION

[0013] With reference to Figures 1-6 of the drawings, a portion of an exemplary electric drive unit 10 that Is constructed In accordance with the teachings of the present disclosure is shown. It will be appreciated that it is well known in the art that an electric drive unit has a housing, an electric motor received in the housing, a transmission driven by the electric motor, and one or more output members, which can be driven directly by the transmission or through a differential assembly that is disposed in a power path between the transmission and a pair of output members. In this regard, and except as noted below, the electric drive unit 10 could have a configuration of the type that is disclosed in International (PCT) Patent Application No. PCT / IB2021 / 052581 filed March 29, 2021.

[0014] The electric drive unit 10 can include a housing 12, a high-voltage interlock circuit 14 and an exterior cover assembly 16.

[0015] The housing 12 is configured to house elements of the electric drive unit 10, such as an electric motor (not shown), a plurality of high-power electric leads (not shown), which electrically couple the electric motor to an inverter (not shown), the high-voltage interlock circuit 14, and various elements of the exterior cover assembly 16. In particular, the housing 12 defines a cavity 18 into which the interlock circuit 14 and the high-power electric leads are disposed. The cavity 18 extends through an opening 20 in the housing 12.

[0016] The high-voltage interlock circuit 14 can include a circuit board having a sensing circuit (not shown) that includes first and second sensing leads 22 and 24. The first and second sensing leads 22 and 24 are formed of an electrically conductive material, such as copper, and are fixedly coupled to a cover connector assembly 26 that electrically isolates the high-voltage interlock circuit 14 from the housing 12. The high-voltage interlock circuit 14 operates in a first mode that permits the transmission of electrical power between the inverter and the electric motor when electrical power is transmitted between the first and second sensing leads 22 and 24. The high-voltage interlock circuit 14 operates in a second mode that inhibits the transmission of electrical power between the inverter and the electric motor when electrical power is not transmitted between the first and second sensing leads 22 and 24. The circuit board is disposed in the cavity 18 and coupled to the housing 12 as well as the first and second sensingterminals 22 and 24. The cover connector assembly 26 can interact with a vehicle battery to remove battery voltage to the electric motor and cable systems.

[0017] An implementation of the cover connector assembly 26 includes a connector housing 28 and a frame 30 that couples the assembly 26 to the housing 12. The frame 30 can include a plurality of apertures used to mount the cover connector assembly 26 to the housing 12. The cover connector assembly 26 can omit at least some of the mechanical elements used to implement a switch. For example, pivots and / or springs typically used in a switch implementation may be omitted. This can help prevent functionality failures. First and second sensing connectors 32 and 34 can be electrically coupled to the first and second sensing leads 22 and 24, respectively, and configured to receive electrical terminals of a busbar. The cover connector assembly 26 is configured to removably receive a disconnect jumper assembly 36 that selectively conducts electrical current between the first and second sensing connectors 32 and 34 depending on the position of the exterior cover assembly 16 relative to the housing 12.

[0018] The connector housing 28 may be formed from an electrically- insulating material and shaped to include wire conduits for receiving and routing the first and second sensing leads 22 and 24 as well as connector receptacles 38 that orient and hold the first and second sensing connectors 32 and 34. One or more wire conduits 40 can be integrally formed in the connector housing 28 and be shaped in one of a variety of ways. For example, the wire conduits 40a could be notches or reliefs in the surface of the housing that provide space and / or location for the sensing leads. Or in another example, the wire conduits 40b canhave a channel that cabins in the sensing leads 22 and 24 on opposite sides. Depending on the implementation, the connector housing 28 can be relatively elongated having a central spine 42 that positions the first and second sensing connectors 32 and 34 a distance from a planar mounting surface.

[0019] The connector receptacles 38 can be formed or positioned at one end of the connector housing 28. In one implementation, the connector receptacles 38 can be roughly U-shaped with opposing planar tangs 44 that are spaced apart and attached to the central spine 42. The planar tangs 44 are spaced apart and made from a material such that during insertion of the sensing connectors 32 and 34 into the connector receptacles 38 the planar tangs 44 move away from each other but once the sensing connectors 32 and 34 abut the central spine 42 the planar tangs 44 move toward each other thereby cabining in the sensing connectors 32 and 34 and holding them in place. Movement can further be constrained by using a lip 46 positioned in between the planar tangs 44 that abuts a portion of the sensing connectors 32 and 34. The connector housing 28 having the planar mounting surface may be shaped to abut the frame 30 and orient the housing 28 relative to the frame 30. The sensing connectors 32 and 34 can be implemented in a number of different ways. For example, the sensing connectors 32 and 34 can be implemented as spade female connectors. An aperture can be included in the planar mounting surface and sized to receive a fastener 48, such as a threaded bolt, that passes through the aperture and engages with the frame 30 and / or the housing 12.

[0020] The disconnect jumper assembly 36 includes a base 50, at least one insulator 52, and a busbar 54. The disconnect jumper assembly 36 is configured to removably engage the busbar 54 with the sensing connectors 32 and 34 in order to complete or close a sensing circuit while the exterior cover assembly 16 abuts the housing 12 and closes the cavity 18. When the exterior cover assembly 16 is removed from the housing 12, the disconnect jumper assembly 36 can move with the exterior cover assembly 16 disengaging the busbar 54 from the sensing connectors 32 and 34, opening or breaking the sensing circuit. The base 50 can include a planar section 58 that may be bonded to or otherwise attached to a surface of the exterior cover assembly 16 that faces the cavity 18. It is possible to weld the base 50 to the exterior cover assembly 16 or bond it using an adhesive. A plurality of rails 60 can be attached to the planar section 58 such that the rails 60 prevent movement of the insulator(s) 52 and busbar 54 in at least one direction. An end stop 62 can prevent linear movement of the insulator(s) 52 and the busbar 54. The rails 62 can be shaped to closely conform to an outer surface of the insulator(s) 52.

[0021] In this implementation, two insulators 52 can receive and fixedly hold the busbar 54. The insulators 52 can include a cavity 64 for receiving a portion of the busbar 54 such that the cavity 64 is partially defined by a slot 66 permitting the busbar 54 to extend outside and away from the insulator 52. The insulators 52 can be open on one end to permit the busbar 54 to slide into the cavity 64. The busbar 54 can include two relatively planar blades 68 and a plurality of planar tangs 70. The planar blades 68 may be sized and shaped so that they can be removablyreceived by the sensing connectors 32 and 34. The tangs 70 can engage an inner surface of the cavity 64 and iocate the busbar 42 with respect to the insulator(s) 52. The busbar 54 can be made from any one of a number of different electrically- conductive materiais, such as copper, it is possibie to stamp the busbar 54 from sheets of material and iater bend the material into a final form.

[0022] Transmission of electrical power through the sensing circuit of the high-voltage interlock circuit 14, and in particular in an electrical path directly between the first sensing connector 32, the busbar 54, and the second sensing connector 34 causes the high-voltage interlock circuit 14 to operate in the first mode that permits the transmission of electrical power between the inverter and the electric motor. Thereafter, the removal of the exterior cover assembly 16 to permit access to the cavity 18 effectively electrically decouples the busbar 54 from the sensing connectors 32 and 34 to interrupt or inhibit the transmission of electrical power through the sensing circuit of the high-voltage interlock circuit 14, which causes the high-voltage interlock circuit 14 to operate in the second mode that inhibits the transmission of electrical power between the inverter and the electric motor.

[0023] It should be appreciated that the configuration of the high-voltage interlock circuit 14 and the exterior cover assembly 16 is such that electrical power cannot be transmitted through the sensing circuit if the exterior cover assembly 16 is not installed. In such situations, the high-voltage interlock circuit 14 will operate in the second mode to inhibit the transmission of electrical power between the inverter and the electric motor.

[0024] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

IN THE CLAIMS:1 . A high-voltage interlock (HVIL) circuit for an electric drive unit in a vehicle, comprising: a frame, configured to couple to a housing of the electric drive unit, including: a first connector receptacle that is configured to releasably and electrically couple with a first portion of a busbar; a second connector receptacle that is configured to releasably and electrically couple with a second portion of the busbar; a disconnect jumper assembly, configured to couple to a removable cover assembly of the housing, including: the busbar, having the first portion of the busbar configured to releasably and electrically connect with the first connector receptacle; the second portion of the busbar configured to releasably and electrically connect with the second connector receptacle, wherein the HVIL is in a conductive mode while the first portion of the busbar is electrically coupled to the first connector receptacle and the second portion of the busbar is electrically coupled to the second connector receptacle; and the HVIL is in a non-conductive mode while the first sensing connector and the second sensing connector are separated from the busbar.

2. The HVIL circuit recited in claim 1 , wherein the first portion of the busbar and the second portion of the busbar have a planar shape.

3. The HVIL circuit recited in claim 1 , further comprising wire conduits that receive a first sensing lead and a second sensing lead.

4. The HVIL circuit recited in claim 1 , wherein the frame includes a central spine that positions the first connector receptacle and the second connector receptacle with respect to the removable cover assembly.

5. The HVIL circuit recited in claim 1 , further comprising opposing planar tangs that abut the first connector receptacle and the second connector receptacle.

6. The HVIL circuit recited in claim 5, wherein the opposing planar tangs extend away from a central spine.

7. The HVIL circuit recited in claim 5, wherein the opposing planar tangs include a lip that abuts a portion of the first sensing connector and the second sensing connector.

8. The HVIL circuit recited in claim 1 , wherein the first sensing connector and the second sensing connector are spade female connectors.

9. The HVIL circuit recited in claim 1 , further comprising the removable cover assembly having a plurality of rails that prevent movement of an insulator relative to the busbar.

10. The HVIL circuit recited in claim 1 , wherein the disconnect jumper assembly further comprises a base and an insulator that abuts the busbar.

11. The HVIL circuit recited in ciaim 10, wherein the insulator includes a cavity for receiving a portion of the busbar.

12. The HViL circuit recited in claim 11 , wherein the busbar includes tangs that engage an inner surface of the cavity and locate the busbar with respect to the insulator.

13. A high-voltage interlock (HViL) circuit for an electric drive unit in a vehicle, comprising: a frame, configured to couple to a housing of the electric drive unit, having a planar mounting surface and a central spine with planar tangs, including: a first connector receptacle held between the planar tangs that is configured to releasably and electrically couple with a first portion of a busbar; a second connector receptacle held between the planar tangs that is configured to releasably and electrically couple with a second portion of the busbar; a disconnect jumper assembly, configured to couple to a removable cover assembly of the housing, including: the busbar, having the first portion of the busbar configured to releasably and electrically connect with the first connector receptacle; the second portion of the busbar configured to releasably and electrically connect with the second connector receptacle,wherein the HVIL is in a conductive mode while the first portion of the busbar is electrically coupled to the first connector receptacle and the second portion of the busbar is electrically coupled to the second connector receptacle; and the HVIL is in a non-conductive mode while the first sensing connector and the second sensing connector are separated from the busbar.

14. The HVIL circuit recited in claim 13, further comprising wire conduits that receive a first sensing lead and a second sensing lead.

15. The HVIL circuit recited in claim 13, wherein the planar tangs include a lip that abuts a portion of the first sensing connector and the second sensing connector.

16. The HVIL circuit recited in claim 13, wherein the first sensing connector and the second sensing connector are spade female connectors.

17. The HVIL circuit recited in claim 13, further comprising the removable cover assembly having a plurality of rails that prevent movement of an insulator relative to the busbar.

18. The HVIL circuit recited in claim 13, wherein the disconnect jumper assembly further comprises a base and an insulator that abuts the busbar.

19. The HVIL circuit recited in claim 18, wherein the insulator includes a cavity for receiving a portion of the busbar.

20. The HVIL circuit recited in claim 18, wherein the busbar includes tangs that engage an inner surface of the cavity and locate the busbar with respect to the insulator.