Transmission with ventilated terminal strip

Abstract

The invention provides a transmission with a ventilated terminal block. A hybrid transmission has a housing with two chambers. One chamber accommodates electric motors and other transmission components that require liquid lubricant and coolant, such as automatic transmission oil. The other chamber accommodates power electronics that must be isolated from the liquid lubricant / coolant. In order to reduce the number of breather pipes required, this is beneficial if air can move between the chambers. A terminal strip cooperates with a partition wall between the two chambers to create a labyrinth seal between the chambers.

Description

Technical Field

[0001] The present invention relates to a hybrid transmission. More specifically, the present disclosure relates to a terminal block installed between two sealed chambers of a transmission housing. Background Art

[0002] Automotive transmissions typically utilize a sealed housing. Temperature changes can increase or decrease the pressure of the air inside the housing relative to the external pressure. A breather is typically installed to allow air to flow in both directions between the housing and the surrounding environment. The path of the breather tube must be carefully selected to prevent the ingestion of contaminants from the surrounding environment into the transmission housing. Summary of the invention

[0003] A hybrid transmission assembly includes a transmission housing, a terminal block, at least one motor, and a power electronics module. The transmission housing defines a first chamber and a second chamber separated by a wall defining an opening. The wall may define a plurality of grooves at least partially surrounding the opening. The terminal block is fastened to the wall and has a plurality of conductive terminals extending through the opening. The terminal block and the wall cooperate to define a labyrinth seal that allows bidirectional air exchange between the first chamber and the second chamber while preventing liquid from flowing from the first chamber to the second chamber. For example, the terminal block may have a plurality of ridges extending into the groove to establish a labyrinth seal. The terminal block may define at least one vent hole that fluidly connects the labyrinth seal to the top surface of the terminal block. The terminal block may be fastened to the wall using bolts. The at least one motor located in the first chamber is electrically connected to the plurality of terminals. The power electronics module located in the second chamber is also electrically connected to the plurality of terminals and is configured to provide power to the at least one motor. A vent may extend between the exterior of the housing and one and only one of the first chamber and the second chamber.

[0004] A hybrid transmission assembly includes a transmission housing, a terminal row and a vent. The transmission housing defines a first chamber and a second chamber, the first chamber and the second chamber being separated by a wall defining an opening. The terminal row is fastened to the wall, for example, by bolts and has a plurality of conductive terminals extending through the opening. The terminal row and the wall are configured to allow two-way air exchange between the first chamber and the second chamber while preventing liquid from flowing from the first chamber to the second chamber. The vent is configured to allow air to flow between an environment outside the housing and one of the first chamber and the second chamber. The wall may define a plurality of grooves at least partially surrounding the opening, and the terminal row may have a plurality of ridges extending into the grooves to establish a labyrinth seal. The terminal row may define at least one vent hole, the at least one vent hole fluidly connecting the labyrinth seal to the top surface of the terminal row. Alternatively, the terminal row may include a first portion defining a plurality of grooves and a second portion having a plurality of ridges extending into the grooves to establish a labyrinth seal. The hybrid transmission assembly may also include at least one motor in the first chamber, the at least one motor being electrically connected to the plurality of terminals. A power electronics module may be housed in the second chamber and electrically connected to the plurality of terminals and configured to provide power to the at least one motor.

[0005] A terminal block includes a non-conductive body and a plurality of conductive terminals. The non-conductive body has a first surface and a second surface. The plurality of conductive terminals extend through the body and protrude from the first surface and the second surface. The body has a series of ridges configured to cooperate with grooves of a mating portion to define a labyrinth seal that allows two-way air exchange between the first surface and the second surface while preventing liquid from flowing from the first surface to the second surface. The non-conductive body may define at least one vent that fluidly connects the labyrinth seal to the top surface of the non-conductive body. The mating portion may be a wall that separates two chambers of a housing of a transmission assembly. Alternatively, both the mating portion and the non-conductive body may be made of plastic and may be joined together. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 A block diagram of an electric vehicle is shown.

[0007] Figure 2 Shows that it is suitable for Figure 1 A hybrid transmission assembly used in a vehicle.

[0008] Figure 3A is used in Figure 2 A top view of a first embodiment of a terminal block for use in a transmission.

[0009] Figure 3B yes Figure 3A Cross-sectional view of a terminal strip.

[0010] Figure 4A is used in Figure 2 A top view of a second embodiment of a terminal block for use in a transmission.

[0011] Figure 4B yes Figure 4A First cross-sectional view of a terminal strip.

[0012] Figure 4C yes Figure 4A Second cross-sectional view of the terminal strip.

[0013] Figure 5A is used in Figure 2 A top view of a third embodiment of a terminal block for use in a transmission.

[0014] Figure 5B yes Figure 5A Cross-sectional view of a terminal strip. DETAILED DESCRIPTION

[0015] Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention that may be embodied in various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to utilize the present invention in various forms.

[0016] Reference now Figure 1 , a block diagram of an exemplary electric vehicle ("EV") 12 is shown. In this example, the EV 12 is a plug-in hybrid electric vehicle (PHEV). The EV 12 includes one or more electric machines 14 that are mechanically connected to a transmission 16. The electric machine 14 is capable of operating as a motor and a generator. The transmission 16 is mechanically connected to an engine 18 and a drive shaft 20 that is mechanically connected to wheels 22. The electric machine 14 can provide propulsion and retarding capabilities when the engine 18 is turned on or off. The electric machine 14 acting as a generator can recover energy that might normally be lost as heat in a friction braking system. The electric machine 14 can reduce vehicle emissions by allowing the engine 18 to operate at a more efficient speed and allowing the EV 12 to operate in an electric mode with the engine 18 turned off under certain conditions.

[0017] The traction battery 24 ("battery") stores energy that can be used by the motor 14 to propel the EV 12. The battery 24 generally provides a high voltage (HV) direct current (DC) output. The battery 24 is electrically connected to a power electronics module 26. The power electronics module 26 is electrically connected to the motor 14 and provides the ability to transfer energy bidirectionally between the battery 24 and the motor. For example, the battery 24 may provide a DC voltage, while the motor 14 may require a three-phase alternating current (AC) voltage to operate. The power electronics module 26 may convert the DC voltage to a three-phase AC voltage to operate the motor 14. In a regenerative mode, the power electronics module 26 may convert the three-phase AC voltage from the motor 14 acting as a generator to a DC voltage that is compatible with the battery 24.

[0018] The battery 24 can be recharged by an external power source 36 (e.g., an electrical grid). An electric vehicle supply equipment (EVSE) 38 is connected to the external power source 36. The EVSE 38 provides circuits and controls to control and manage the energy transfer between the external power source 36 and the EV 12. The external power source 36 can provide DC or AC power to the EVSE 38. The EVSE 38 can have a charging connector 40 for plugging into a charging port 34 of the EV 12. The charging port 34 can be any type of port configured to transfer power from the EVSE 38 to the EV 12. The power conversion module 32 of the EV 12 can condition the power supplied from the EVSE 38 to provide the appropriate voltage and current levels to the battery 24. The power conversion module 32 can interface with the EVSE 38 to coordinate the power delivery to the battery 24. Alternatively, the various components described as being electrically connected can use wireless inductive coupling to transfer power.

[0019] Wheel brakes 44 are provided to slow and prevent movement of the EV 12. The wheel brakes 44 are part of a braking system 50. The braking system 50 may include a controller to monitor and control the wheel brakes 44 to achieve desired operation.

[0020] The various components discussed may have one or more associated controllers to control and monitor the operation of the components. The controllers may be microprocessor-based devices. The controllers may communicate via a serial bus (e.g., a controller area network (CAN)) or via discrete conductors. For example, there is a system controller 48 (i.e., a vehicle controller) to coordinate the operation of the various components.

[0021] As depicted, the EV 12 in this example is a PHEV having an engine 18 and a battery 24. In other embodiments, the EV 12 is a battery electric vehicle (BEV). In a BEV configuration, the EV 12 does not include an engine.

[0022] Figure 2The structure of the transmission 16 is schematically shown. The transmission housing includes two separate chambers: a transaxle chamber 60 that houses the motor and gear arrangement and an inverter system controller (ISC) chamber 62 that houses the power electronics module 26. The transmission chamber 60 includes an oil pan filled with automatic transmission oil (ATF) or other suitable liquid lubricant 64. The gear arrangement 66 guides power between the engine 18, the generator 14A, the motor 14B and the drive shaft 20. The generator 14A and the motor 14B can be permanent magnet synchronous motors or other suitable types of electric motors. The liquid lubricant 64 lubricates the gear arrangement 66 and removes heat from the generator 14A, the motor 14B and the gear arrangement. The liquid lubricant can be distributed between these components using a pump, or it can be distributed by splashing into the components in the oil pan area. The two chambers are separated from each other by a terminal strip 68. The two separate chambers allow the power electronics module 26 to be isolated from the liquid lubricant 64. The air temperature in the two chambers changes during operation. The vent 70 is used to maintain pressure balance between the chamber and the surrounding environment. As the interior air heats up, the air escapes to the environment through the breather 70. As the interior air cools, the air enters the chamber through the breather 70. The breather outlet is strategically located so that contaminants do not enter the housing through the breather.

[0023] FIG. 3A to FIG. 3B A first embodiment of a terminal block 68 is shown. Figure 3A is a top view, and Figure 3B is a cross-sectional view. The plastic body 72 is fastened to the partition wall over the opening 76 in the partition wall 74. For example, the plastic body 72 can be fastened to the partition wall 74 by bolts 78. A set of six terminals 80 extend through the plastic body. Each terminal carries one phase of the three-phase stator current from the power electronics module 26 to the generator 14A or the motor 14B. The number of terminals can vary based on the transmission kinematic architecture and the type of motor used. A seal 82 is installed between the plastic body and the partition wall 84 surrounding the opening 76. The seal prevents liquid lubricant or air from flowing between the two chambers. Since the two chambers are air-tight to each other, two vents are required, one vent for each of the two chambers.

[0024] FIG. 4A to FIG. 4C A second embodiment of a terminal block 68 ′ is shown. Figure 4A is a top view, and Figure 4B and Figure 4C is a cross-sectional view. The plastic body 72' is secured to the partition wall over the opening 76 in the partition wall 74'. A set of six terminals 80 extend through the plastic body as in the first embodiment. Figure 4B and Figure 4CAs shown, a plurality of grooves 82 are formed in the partition wall 74' surrounding the opening. A set of ridges 84 are formed in the plastic body 72', which fit into these grooves. The width and depth of the grooves and ridges and the spacing between them are selected so that the ridges extend into the grooves, but the surfaces do not touch. Therefore, a circuitous path 86 is defined between the plastic body and the partition wall. (Contact at some circumferential positions may be acceptable.) Vents 88 at one or more circumferential positions define a passage from the circuitous path 86 to the top surface of the plastic body 72'. The circuitous path 86 and the vents 88 form a labyrinth seal that prevents liquid lubricant from flowing between the two chambers, but allows air exchange between the chambers. Since bidirectional airflow between the chambers is allowed, one vent located in either chamber is sufficient.

[0025] FIG. 5A to FIG. 5B A third embodiment of a terminal block 68" is shown. Figure 5A is a top view, and Figure 5B is a cross-sectional view. In this embodiment, the plastic body is made of two parts 72" and 90. A labyrinth seal is formed between the two parts. The first part 90 is fastened to the partition wall 74 above the opening 76. The set of six terminals 80 extends through the second part 72". Figure 5B As shown, a plurality of grooves 82' are formed in the first portion 90. A set of ridges 84 are formed in the second portion 72", which fit into these grooves. The width and depth of the grooves and ridges and the spacing therebetween are selected so that the ridges extend into the grooves, but the surfaces do not touch. The two portions 90 and 72" are fused together at several locations around the circumference to form a terminal strip assembly. A circuitous path 86 is defined between the two portions that are not fused together at the circumferential positions. The labyrinth seal thus formed prevents liquid lubricant from flowing between the two chambers, but allows air to flow between the chambers. As with the second embodiment, one vent located in either chamber is sufficient. There is no need to modify the partition wall 74 from the first embodiment.

[0026] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms of the present invention. Rather, the words used in the specification are descriptive rather than restrictive terms, and it should be understood that various changes can be made without departing from the spirit and scope of the present invention. In addition, the features of the various embodiments of implementation can be combined to form other embodiments of the present invention.

[0027] According to the present invention, a hybrid transmission assembly is provided, which has: a transmission housing defining a first chamber and a second chamber, the first chamber and the second chamber being separated by a wall defining an opening; a terminal row, the terminal row being fastened to the wall and having a plurality of conductive terminals extending through the opening, the terminal row and the wall cooperating to define a labyrinth seal, the labyrinth seal allowing two-way air exchange between the first chamber and the second chamber while preventing liquid from flowing from the first chamber to the second chamber; at least one motor in the first chamber, the at least one motor being electrically connected to the plurality of terminals; and a power electronics module in the second chamber, the power electronics module being electrically connected to the plurality of terminals and configured to provide power to the at least one motor.

[0028] According to an embodiment, the wall defines a plurality of grooves at least partially surrounding the opening, and the terminal block has a plurality of ridges extending into the grooves to establish the labyrinth seal.

[0029] According to an embodiment, the terminal block defines at least one vent hole, the at least one vent hole fluidly connecting the labyrinth seal to a top surface of the terminal block.

[0030] According to an embodiment, the terminal block is fastened to the wall using bolts.

[0031] According to an embodiment, the invention also features a breather between the exterior of the housing and one of the first chamber and the second chamber.

[0032] According to an embodiment, no vent directly connects the second of the first chamber and the second chamber to the outside.

[0033] According to the present invention, a hybrid transmission assembly is provided, which has: a transmission housing defining a first chamber and a second chamber, the first chamber and the second chamber being separated by a wall defining an opening; a terminal row, the terminal row being fastened to the wall and having a plurality of conductive terminals extending through the opening, the terminal row and the wall being configured to allow two-way air exchange between the first chamber and the second chamber while preventing liquid from flowing from the first chamber to the second chamber; and a vent, the vent being configured to allow air to flow between an environment outside the housing and one of the first chamber and the second chamber.

[0034] According to an embodiment, the wall defines a plurality of grooves at least partially surrounding the opening, and the terminal block has a plurality of ridges extending into the grooves to establish a labyrinth seal.

[0035] According to an embodiment, the terminal block defines at least one vent hole, the at least one vent hole fluidly connecting the labyrinth seal to a top surface of the terminal block.

[0036] According to an embodiment, the terminal block includes a first portion defining a plurality of grooves and a second portion having a plurality of ridges extending into the grooves to establish a labyrinth seal.

[0037] According to an embodiment, the terminal block is fastened to the wall using bolts.

[0038] According to an embodiment, the present invention is also characterized by at least one motor in the first chamber, the at least one motor being electrically connected to the plurality of terminals.

[0039] According to an embodiment, the invention is also characterized by a power electronics module in the second chamber, the power electronics module being electrically connected to the plurality of terminals and configured to provide power to the at least one motor.

[0040] According to the present invention, a terminal block is provided, which comprises: a non-conductive body having a first surface and a second surface; and a plurality of conductive terminals extending through the body and protruding from the first surface and the second surface; wherein the body has a series of ridges, the ridges being configured to cooperate with grooves of a mating portion to define a labyrinth seal, the labyrinth seal allowing bidirectional air exchange between the first surface and the second surface while preventing liquid from flowing from the first surface to the second surface.

[0041] According to an embodiment, the non-conductive body defines at least one vent hole, the at least one vent hole fluidly connecting the labyrinth seal to the top surface of the non-conductive body.

[0042] According to an embodiment, the mating portion is a wall separating two chambers of a housing of the transmission assembly.

[0043] According to an embodiment, the invention also features a mating portion, wherein the mating portion is joined to the non-conductive body, and both the non-conductive body and the mating portion are made of plastic.

[0044] According to an embodiment, the plurality of electrically conductive terminals includes six terminals.

Claims

1. A hybrid transmission assembly, comprising: a transmission housing defining a first chamber and a second chamber, the first chamber and the second chamber being separated by a wall defining an opening; a terminal block secured to the wall and having a plurality of conductive terminals extending through the opening, the terminal block and the wall cooperating to define a labyrinth seal that allows bidirectional air exchange between the first chamber and the second chamber while preventing liquid from flowing from the first chamber to the second chamber; at least one motor in the first chamber, the at least one motor electrically connected to the plurality of terminals; and A power electronics module in the second compartment is electrically connected to the plurality of terminals and is configured to provide power to the at least one motor. 2 . The hybrid transmission assembly of claim 1 , wherein said wall defines a plurality of grooves at least partially surrounding said opening, and said terminal block has a plurality of ridges extending into said grooves to establish said labyrinth seal. 3 . The hybrid transmission assembly of claim 2 , wherein the terminal block defines at least one vent hole, the at least one vent hole fluidly connecting the labyrinth seal to a top surface of the terminal block. 4 . The hybrid transmission assembly of claim 1 , further comprising a breather between an exterior of the housing and one of the first chamber and the second chamber. 5 . The hybrid transmission assembly of claim 4 , wherein no breather directly connects the second of the first chamber and the second chamber to the exterior.

6. A hybrid transmission assembly, comprising: a transmission housing defining a first chamber and a second chamber, the first chamber and the second chamber being separated by a wall defining an opening; a terminal block secured to the wall and having a plurality of conductive terminals extending through the opening, the terminal block and the wall being configured to allow bidirectional air exchange between the first chamber and the second chamber while preventing liquid from flowing from the first chamber to the second chamber; and A breather is configured to allow air to flow between an environment external to the housing and one of the first chamber and the second chamber. 7 . The hybrid transmission assembly of claim 6 , wherein said wall defines a plurality of grooves at least partially surrounding said opening, and said terminal block has a plurality of ridges extending into said grooves to establish a labyrinth seal. 8 . The hybrid transmission assembly of claim 7 , wherein said terminal block defines at least one vent hole, said at least one vent hole fluidly connecting said labyrinth seal to a top surface of said terminal block. 9 . The hybrid transmission assembly of claim 6 , wherein said terminal block includes a first portion defining a plurality of grooves and a second portion having a plurality of ridges extending into said grooves to establish a labyrinth seal.

10. The hybrid transmission assembly of claim 6, wherein said terminal block is fastened to said wall using bolts.

11. The hybrid transmission assembly of claim 6, further comprising: at least one motor in the first chamber, the at least one motor electrically connected to the plurality of terminals; and A power electronics module in the second compartment is electrically connected to the plurality of terminals and is configured to provide power to the at least one motor.

12. A terminal block comprising: a non-conductive body having a first surface and a second surface; and a plurality of conductive terminals extending through the body and protruding from the first surface and the second surface; The body has a series of ridges configured to cooperate with grooves of the mating portion to define a labyrinth seal that allows two-way air exchange between the first surface and the second surface while preventing liquid from flowing from the first surface to the second surface.

13. The terminal block of claim 12, wherein the non-conductive body defines at least one vent hole, the at least one vent hole fluidly connecting the labyrinth seal to the top surface of the non-conductive body.

14. The terminal block of claim 12, wherein the mating portion is a wall separating two chambers of a housing of a transmission assembly.

15. The terminal block of claim 12, further comprising a mating portion, wherein the mating portion is engaged to the non-conductive body, and both the non-conductive body and the mating portion are made of plastic.

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