Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of the invention:
[0001] The present invention relates to a high voltage interface for an electric machine and the electric machine.

Background of the invention:
[0002] A High Voltage (HV) interface aims to provide assembly interface between bus bars from power electronics and bus bars from a stator of an electric machine such as an electric motor. To ensure the final assembly, all the assembly tolerances from stator pins connection to housing assembly need to be compensated. Currently known products use flexible lamella bands or cable connection which offers flexibility to compensate for existing assembly tolerances. These techniques can lead to below issues, handling problems of the copper flexible parts in the assembly, vibration cracks on the lamella bands of copper flexible part, additional insulation of cables to ensure air distances, and metal particles from woven cable falling into the stator and creating cleanliness problems.

[0003] According to a patent literature DE102015226027, an Oil-tight electrical connection device is disclosed. A connection device for connecting a cable to at least one electrical phase conductor of an electrical assembly comprises at least one electrically conductive connecting element for the at least one phase conductor, wherein the connecting element has a blind hole-shaped cable connection opening to which the phase conductor can be connected; and an insulating unit which has at least one through-opening, wherein the through-opening is designed to receive a connecting element in a sealing manner. The insulating unit is designed to be slipped over the at least one phase conductor protruding from the electrical assembly, so that the phase conductor protrudes into the through-opening. The connecting element is designed in one piece and has a blind hole-shaped phase connection opening which is opposite the cable connection opening in an axial direction of the connecting element and in which the phase conductor can be received.

Brief description of the accompanying drawings:
[0004] An embodiment of the disclosure is described with reference to the following accompanying drawings,
[0005] Fig. 1 illustrates a top perspective view and a bottom view of a high voltage interface, according to an embodiment of the present invention;
[0006] Fig. 2 illustrates a bottom perspective view and a side cross-section view of the high voltage interface, according to an embodiment of the present invention;
[0007] Fig. 3 illustrates an electric machine with the high voltage interface, according to an embodiment of the present invention, and
[0008] Fig. 4 illustrates an assembly of high voltage interface on the electric machine, according to an embodiment of the present invention.

Detailed description of the embodiments:
[0009] Fig. 1 illustrates a top perspective view and a bottom view of a high voltage interface, according to an embodiment of the present invention. The high voltage interface 100 is for an electric machine 300 (shown in Fig. 3). The high voltage interface 100 comprises a frame 102 with over-molded threaded inserts 112. The frame 102 comprises a first end 104 and a second end 118. The threaded inserts 112 are provided for electrical connections, characterized in that, the first end 104 comprises a cavity 114 with a guide pin 116, and the second end 118 comprises a snap-lock feature. The first end 104 and the second end 118 enables mounting of the high voltage interface 100 on to a housing (enclosure) 302 (shown in the Fig. 3) of the electric machine 300. The electrical connection is between the busbars 304 of the stator of the electric machine 300 and the power electronics circuitry (not shown).

[0010] In Fig. 1, the top perspective view 110 is the first figure followed by the bottom view 120. The first end 104 and the second end 118 provides a floating type interfacing over the housing 302 of the electric machine 300. The cavity 114 and the guide pin 116 are visible in the bottom view 120.

[0011] According to an embodiment of the present invention, the snap-lock feature comprises a stopper 108 and an arm 106 to secure mounting of the frame 102. In other words, the stopper 108 and the arm 106 are also referrable as first arm 106 and a second arm 108.

[0012] Fig. 2 illustrates a bottom perspective view and a side cross-section view of the high voltage interface, according to an embodiment of the present invention. In the bottom perspective view 200, the guide pin 116 is shown to be extending beyond the length of the circumscribing first end 104. Further, the bent shape of the arm 106 and profile of the stopper 108 are also shown.

[0013] In the side cross-section view 210, the high voltage interface 100 is shown in more detail with respect to the over-molded (inset molded) inserts 112. Further the length of the guide pin 116 is greater than the length of the first end 104. The cavity 114 is show clearly between the wall of the first end 104 and the guide pin 116.

[0014] Fig. 3 illustrates an electric machine with the high voltage interface, according to an embodiment of the present invention. The first end 104 is mountable over a first mounting position 402 (shown in Fig. 4) in the housing 302 of the electric machine 300. The second end 118 engages with a second mounting position 404 (shown in Fig. 4) in the housing 302 of the electric machine 300. The first end 104 is pressed or inserted and held on the first mounting position 402 which is a slot and rotated about the axis of the guide pin 116 to engage the second end 118 with the second mounting position 404 which is a dome or any other shape such as another slot.

[0015] According to an embodiment of the present invention, the electric machine 300 is disclosed. The electric machine 300 comprises the housing 302. The housing 302 encloses a rotor and a stator as known in the art. The electric machine 300 also comprises the high voltage interface 100 comprising the frame 102, the frame 102 over-molded with threaded insert 112 and having the first end 104 and the second end 118. The high voltage interface 100 is mounted over the housing 302, and the threaded inserts 112 are provided for electrical connections, characterized in that, the first mounting position 402 and the second mounting position 404 are provided on the housing 302 for secured mounting of the frame 102 using the first end 104 and the second end 118. An assembly 310 of the high voltage interface 100 under the stator bus bar 304 on the housing 302 is depicted.

[0016] Fig. 4 illustrates an assembly of high voltage interface on the electric machine, according to an embodiment of the present invention. In the electric machine 300, the first mounting position 402 pairs with the first end 104 and the second mounting position 404 pairs with the second end 118. The first end 104 is pressed/pushed/ inserted and held as clearance fit on the first mounting position 402 and rotated about the first mounting position 402 to engage the second end 118 with the second mounting position 404. In an embodiment, the first mounting position 402 is the slot in the housing 302, and the second mounting position 404 is the dome on the housing 302. The second end 118 comprises snap-lock feature. The snap-lock feature comprises the stopper 108 and the arm 106 to secure the second end 118 with the second mounting position 404. The second end 118 is in the shape of an arc. Once the second end 118 snapes on the dome, the stopper 108 and the arm 106 are held against the dome with a clearance, which locks but also allows movement within the stopper 108 and the arm 106. The stopper 108 and the arm 106 are designed in a manner to snap onto the second mounting position 404 and lock the movement of the frame 102 with a clearance.

[0017] As can be seen in the front perspective view 400 of the assembly 310, the high voltage interface 100 is positioned under the busbar 304. Once set, the three busbars 304 are screwed with the threaded insert 112 of the high voltage interface 100, thereby establishing electrical connection between the stator of the electric machine 300 and power electronics (not shown). A cross-section view 410 of the assembly 310 shows the assembled state of the high voltage interface 100 before screwing.

[0018] According to the present invention, a floating high voltage interface 100 for the electric machine 300 is provided/disclosed. The floating high voltage interface 100 is an improvement over use of flexible lamella bands or cables to achieve the desired tolerance compensation. The floating high voltage interface 100 provides the interface for power electronics bus bar and stator bus bar connection, compensating the assembly tolerances without the need of additional flexible elements. The high voltage interface 100 comprises the frame 102 (such as made of plastic) with over molded threaded inserts 112 for screwing interface with power electronics bus bars, rigid copper bus bars from stator and mounting features on housing 302 of the electric machine 300. The first end 104 of the frame 102 with its guide pin 116 and snap-lock feature is not entirely fixed to the housing 302 hence called as floating high voltage interface 100 or floating insulating part. The floating insulating part must be assembled by positioning on the guide pin 116 and rotating under the bus bars from stator and then locked to the housing 302 using the locking snap feature. The floating assembly nature of the first end 104 in all three directions in combination with the mounting interface on the housing 302 and mounting hole on the bus bar provides the tolerance compensation to ensure the final assembly of connection bus bars and power electronics bus bars. Dampening elements is possible to be added to the floating insulating part to achieve desired Noise Vibration and Harshness (NVH) levels. The present invention offers cost effective solution, and no additional copper flexible elements needed. Further, easier handling during assembly and transportation, eliminates the cleanliness issues for the stator, and easily achievable electrical air distances of copper parts.

[0019] It should be understood that the embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.
, Claims:We claim:
1. A high voltage interface (100) for an electric machine (300), said high voltage interface (100) comprises:
a frame (102) with over-molded threaded inserts (112), said frame (102) comprises a first end (104) and a second end (118), said threaded inserts (112) are provided for electrical connections, characterized in that,
said first end (104) comprises a cavity (114) with a guide pin (116), and said second end (118) comprises a snap-lock feature, said first end (104) and said second end (118) enables mounting of said high voltage interface (100) on to a housing (302) of said electric machine (300).

2. The high voltage interface (100) as claimed in claim 1, wherein said first end (104) and said second end (118) provides a floating type interfacing over said housing (302) of said electric machine (300).

3. The high voltage interface (100) as claimed in claim 1, wherein said snap-lock feature comprises a stopper (108) and an arm (106) to secure mounting of said frame (102).

4. The high voltage interface (100) as claimed in claim 1, wherein said first end (104) is mountable over a first mounting position (402) in said housing (302) of said electric machine (300), and wherein said second end (118) engages with a second mounting position (404) in said housing (302) of said electric machine (300).

5. The high voltage interface (100) as claimed in claim 4, wherein said first end (104) is pressed on first mounting position (402) through said guide pin (116) and rotated about said axis of said guide pin (116) to engage said second end (118) with second mounting position (404).

6. An electric machine (300), said electric machine (300) comprises:
a housing (302), said housing (302) encloses a rotor and a stator;
a high voltage interface (100) comprising a frame (102), said frame (102) over-molded with threaded insert (112) and having a first end (104) and a second end (118), said high voltage interface (100) is mounted over said housing (302), and said threaded inserts (112) are provided for electrical connections, characterized in that,
a first mounting position (402) and a second mounting position (404) provided on said housing (302) for secured mounting of said frame (102) using said first end (104) and said second end (118).

7. The electric machine (300) as claimed in claim 6, wherein said first mounting position (402) pairs with said first end (104) and said second mounting position (404) pairs with said second end (118).

8. The electric machine (300) as claimed in claim 6, wherein said first end (104) is pressed and held on said first mounting position (402) and rotated about said first mounting position (402) to engage said second end (118) with said second mounting position (404).

9. The electric machine (300) as claimed in claim 6, wherein said first mounting position (402) is a slot in said housing (302), and said second mounting position (404) is a dome in said housing (302).

10. The electric machine (300) as claimed in claim 6, wherein said second end (118) comprises snap-lock feature, wherein said snap-lock feature comprises a stopper (108) and an arm (106) to secure said second end (118) with said second mounting position (404).