GEARBOX WITH VENTILATED CONNECTION BLOCK

Abstract

A hybrid transmission has a housing with two chambers. One chamber contains electric motors and other transmission components that require a liquid lubricant and coolant, such as automatic transmission fluid. The other chamber contains power electronics that must be isolated from the liquid lubricant / coolant. To reduce the required number of vent tubes, it is advantageous for air to be able to move between the chambers. A terminal block works in conjunction with a partition between the two chambers to create a labyrinth seal between them.

Description

AREA OF TECHNOLOGY

[0001] The present invention relates to a hybrid transmission. In particular, the disclosure relates to a connection block that is installed between two sealed chambers of the transmission housing. GENERAL STATE OF THE ART

[0002] Automotive transmissions typically use sealed housings. Temperature changes can increase or decrease the pressure of the air inside the housing relative to the outside pressure. Vents are typically installed to allow air to flow bidirectionally between the housing and the environment. The routing of the vent pipe must be carefully selected to prevent contaminants from the environment from being drawn into the transmission housing. SUMMARY

[0003] A hybrid transmission assembly comprises 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 that defines an opening. The wall may define a plurality of grooves that at least partially surround the opening. The terminal block is attached to the wall and has a plurality of electrically conductive terminals extending through the opening. The terminal block and the wall work together to define a labyrinth seal that allows bidirectional air exchange between the first and second chambers while preventing fluid from flowing from the first chamber into the second. For example, the terminal block may have a series of raised sections that extend into the grooves to form the labyrinth seal.The terminal block can define at least one vent hole that fluidically connects the labyrinth seal to an upper surface of the terminal block. The terminal block can be mounted 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 configured to supply power to the at least one motor. A vent can extend between an outer surface of the enclosure and one, and only one, of the first and second chambers.

[0004] A hybrid transmission assembly comprises a transmission housing, a terminal block, and a vent. The transmission housing defines a first chamber and a second chamber, separated by a wall that defines an opening. The terminal block is attached to the wall, for example by bolts, and has a variety of electrically conductive terminals extending through the opening. The terminal block and wall are configured to allow bidirectional air exchange between the first and second chambers while preventing fluid from flowing from the first chamber into the second. The vent is configured to allow airflow between an environment outside the housing and an environment between the first and second chambers.The wall can define a plurality of grooves that at least partially surround the opening, and the terminal block can have a number of raised sections that extend into the grooves to form a labyrinth seal. The terminal block can define at least one vent hole that fluidically connects the labyrinth seal to an upper surface of the terminal block. Alternatively, the terminal block can include a first part defining a plurality of grooves and a second part with a number of raised sections that extend into the grooves to form a labyrinth seal. The hybrid transmission assembly can further include at least one motor in the first chamber, which is electrically connected to the plurality of terminals. A power electronics module can be housed in the second chamber, electrically connected to the plurality of terminals, and configured to supply power to the at least one motor.

[0005] A terminal block comprises a non-conductive body and a plurality of conductive terminals. The non-conductive body has a first face and a second face. The plurality of electrically conductive terminals extends through the body and projects from the first and second faces. The body has a series of protrusions configured to engage with grooves in a mating component to define a labyrinth seal that allows bidirectional air exchange between the first and second faces while preventing fluid flow from the first to the second face. The non-conductive body may define at least one vent hole that fluidically connects the labyrinth seal to an upper face of the non-conductive body. The mating component may be a wall separating two chambers of a gearbox housing.Alternatively, the counterpart and the non-conductive body can both be made of plastic and connected to each other. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 illustrates a block diagram of an electric vehicle. Fig. Figure 2 illustrates a hybrid transmission assembly designed for use in the vehicle made of Fig. 1 is suitable. Fig. 3A is a top view of a first embodiment of a terminal block for use in the gearbox made of Fig. 2. Fig. 3B is a cross-sectional view of the terminal block made of Fig. 3A. Fig. 4A is a top view of a second embodiment of a terminal block for use in the gearbox made of Fig. 2. Fig. 4B is a first cross-sectional view of the terminal block made of Fig. 4A. Fig. 4C is a second cross-sectional view of the terminal block made of Fig. 4A. Fig. 5A is a top view of a third embodiment of a terminal block for use in the gearbox made of Fig. 2. Fig. 5B is a cross-sectional view of the terminal block made of Fig. 5A. DETAILED DESCRIPTION

[0006] Detailed embodiments of the present invention are disclosed herein; however, it is understood that the disclosed embodiments are merely exemplary of the invention, which can be implemented in various and alternative forms. The figures are not necessarily to scale; some features may be greatly enlarged or reduced to show details of certain components. Accordingly, the specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis to teach those skilled in the art the diverse applications of the present invention.

[0007] With reference to Fig. Figure 1 shows a block diagram of an exemplary electric vehicle (“EV”) 12. In this example, the EV 12 is a plug-in hybrid electric vehicle (PHEV). The EV 12 includes one or more electric machines 14 (“e-machines”) that are mechanically connected to a transmission 16. The electric machine 14 is capable of operating as a motor and as a generator. The transmission 16 is mechanically connected to an internal combustion engine 18 and to a drive shaft 20, which is mechanically connected to wheels 22. The electric machine 14 can provide propulsion and deceleration capabilities while the internal combustion engine 18 is switched on or off. The electric machine 14, when functioning as a generator, can recover energy that would normally be lost as heat in a friction braking system.The electric machine 14 can reduce vehicle emissions by allowing the combustion engine 18 to operate at more efficient speeds, and it allows the EV 12 to operate in electric mode with the combustion engine 18 switched off under certain conditions.

[0008] A traction battery 24 (“battery”) stores energy that can be used by the electric machine 14 to power the EV 12. The battery 24 typically 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 electric machine 14 and provides the capability to transfer energy bidirectionally between the battery 24 and the electric machine. For example, a battery 24 may provide a DC voltage, while the electric machine 14 may require a three-phase alternating voltage (three-phase AC voltage) to operate. The power electronics module 26 can convert the DC voltage into a three-phase AC voltage to operate the electric machine 14.In a regeneration mode, the power electronics module 26 can convert the three-phase AC voltage from the electric machine 14, which acts as a generator, into DC voltage that is compatible with the traction battery 24.

[0009] The battery 24 is rechargeable by an external power source 36 (e.g., the mains). An electric vehicle supply equipment (EVSE) 38 is connected to the external power source 36. The EVSE 38 provides circuitry and controls for managing the transfer of energy between the external power source 36 and the EV 12. The external power source 36 can supply DC or AC electrical power to the EVSE 38. The EVSE 38 may have a charging plug 40 for insertion into a charging port 34 of the EV 12. The charging port 34 can be any type of connector configured to transfer power from the EVSE 38 to the EV 12. A power conversion module 32 of the EV 12 can condition the power supplied by the EVSE 38 to provide the correct voltage and current levels to the battery 24.The power conversion module 32 can interface with the EVSE 38 to coordinate the delivery of power to the battery 24. Alternatively, various components described as electrically connected can transfer power using wireless inductive coupling.

[0010] Wheel brakes 44 are provided to slow down and prevent the movement of the EV 12. 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 the desired operation.

[0011] The various components discussed may have one or more related controllers that manage and monitor the operation of the components. These controllers may be microprocessor-based devices. The controllers may be interconnected via a serial bus (e.g., a Controller Area Network (CAN)) or via separate wires. For example, a system controller 48 (i.e., a vehicle controller) is present to coordinate the operation of the various components.

[0012] As described, the EV 12 in this example is a PHEV, which includes an internal combustion 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 internal combustion engine.

[0013] Fig. Figure 2 schematically illustrates the structure of the gearbox 16. The gearbox housing includes two separate chambers: an axle gearbox chamber 60, which houses the motors and gearing, and a chamber 62 of the inverter system controller (ISC), which houses the power electronics module 26. The gearbox chamber 60 includes a reservoir filled with automatic transmission fluid (ATF) or another suitable liquid lubricant 64. The gearing 66 transmits power between the internal combustion engine 18, a generator 14A, a 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 gearing 66 and dissipates heat from the generator 14A, the motor 14B, and the gearing.The liquid lubricant can be distributed among these components using a pump or can be distributed by components that spray into the sump area. The two chambers are separated from each other by the terminal block 68. The two separate chambers allow the power electronics module 26 to be isolated from the liquid lubricant 64. The air temperature in both chambers changes during operation. A vent 70 is used to maintain pressure equilibrium between the chambers and the environment. When the internal air heats up, air escapes to the environment through the vent 70. When the internal air cools down, air enters the chambers through the vent 70. The vent outlet is strategically positioned to prevent contaminants from entering the housing through the vent.

[0014] The Fig. Figures 3A-3B illustrate a first embodiment of a terminal block 68. Fig. 3A is a top view, while Fig. Figure 3B shows a cross-sectional view. A plastic body 72 is attached to the partition 74 over an opening 76 in the partition. For example, the plastic body 72 can be attached to the partition 74 by bolts 78. A set of six terminals 80 extends through the plastic body. Each terminal carries one phase of the three-phase stator current from the power electronics module 26 to either the generator 14A or the motor 14B. The number of terminals can vary based on the kinematic architecture of the gearbox and the type of motor used. A seal 82 is installed between the plastic body and the partition 84, which surrounds the opening 76. This seal prevents the flow of either liquid lubricant or air between the two chambers. Since the two chambers are airtight from each other, two vents are required, one for each of the two chambers.

[0015] The Fig. Figures 4A-4C illustrate a second embodiment of a terminal block 68'. Fig. 4A is a top view, while the Fig. 4B and Fig. 4C cross-sectional views are shown. A plastic body 72' is attached to the partition 74' above an opening 76 in the partition. A set of six connectors 80 extends through the plastic body as in the first embodiment. As in the Fig. 4B and Fig. As shown in Figure 4C, a series of grooves 82 are formed in the partition 74' that surrounds the opening. A set of protrusions 84 is formed in the plastic body 72' that fit into these grooves. The width and depth of the grooves and protrusions, as well as the spacing between them, are selected such that the protrusions extend into the grooves, but the surfaces do not touch. As a result, a serpentine path 86 is defined between the plastic body and the partition. (Contact at some points in the circumferential direction may be acceptable.)

[0016] Ventilation openings 88 at one or more points in the circumferential direction define a passage from the coiled path 86 to the upper surface of the plastic body 72'. The coiled path 86 and the ventilation openings 88 form a labyrinth seal that prevents the flow of liquid lubricant between the two chambers but allows air exchange between them. Since bidirectional airflow between the chambers is permitted, a single vent located in one of the chambers is sufficient.

[0017] The Fig. Figures 5A-5B illustrate a third embodiment of a terminal block 68". Fig. 5A is a top view, while Fig. Figure 5B is a cross-sectional view. In this embodiment, the plastic body consists of two parts, 72" and 90". The labyrinth seal is formed between the two parts. The first part, 90, is attached to the partition 74 above the opening 76. The set of six connectors 80 extends through the second part, 72". As shown in Fig.As shown in Figure 5B, a number of grooves 82' are formed in the first part 90. In the second part 72", a set of protrusions 84 is formed that fit into these grooves. The width and depth of the grooves and protrusions, as well as the spacing between them, are selected such that the protrusions extend into the grooves, but the surfaces do not touch. The two parts 90 and 72" are fused together at several points around the circumference to form a terminal block assembly. A winding path 86 is defined between two parts at the circumferential points that are not fused together. The labyrinth seal thus formed prevents a flow of liquid lubricant between the two chambers but allows airflow between them. As in the second embodiment, a vent located in one of the chambers is sufficient. The partition 74 does not need to be modified compared to the first embodiment.

[0018] Although exemplary embodiments have been described above, it is not intended that these embodiments describe all possible forms of the present invention. Rather, the terms used in the description are descriptive and not limiting, and it is understood that various modifications can be made without departing from the essence and scope of the present invention. In addition, the features of different implementing embodiments can be combined to form further embodiments of the present invention.

[0019] According to the present invention, a hybrid transmission assembly is provided comprising: a transmission housing defining a first chamber and a second chamber, wherein the first and second chambers are separated by a wall defining an opening; a terminal block attached to the wall and having a plurality of electrically conductive terminals extending through the opening, wherein the terminal block and the wall interact to define a labyrinth seal that allows bidirectional air exchange between the first and second chambers while preventing fluid from flowing from the first chamber to the second chamber; at least one motor in the first chamber electrically connected to the plurality of terminals;and a power electronics module in the second chamber, which is electrically connected to the multitude of terminals and is configured to provide power to the at least one motor.

[0020] According to one embodiment, the wall defines a plurality of grooves that at least partially surround the opening, and the connecting block has a number of protrusions that extend into the grooves to form the labyrinth seal.

[0021] According to one embodiment, the terminal block defines at least one ventilation hole that fluidically connects the labyrinth seal to an upper surface of the terminal block.

[0022] According to one embodiment, the terminal block is attached to the wall using bolts.

[0023] According to one embodiment, the invention is further characterized by a vent between an outer surface of the housing and one of the first chamber and the second chamber.

[0024] According to one embodiment, no vent connects a second chamber of the first and the second chamber directly to the outside.

[0025] According to the present invention, a hybrid transmission assembly is provided comprising: a transmission housing defining a first chamber and a second chamber, wherein the first and second chambers are separated by a wall defining an opening; a terminal block attached to the wall and having a plurality of electrically conductive terminals extending through the opening, wherein the terminal block and the wall are configured to allow bidirectional air exchange between the first and second chambers while preventing fluid from flowing from the first chamber to the second chamber; and a vent configured to allow airflow between an environment outside the housing and one from the first and second chambers.

[0026] According to one embodiment, the wall defines a plurality of grooves that at least partially surround the opening, and the terminal block has a number of protrusions that extend into the grooves to form a labyrinth seal.

[0027] According to one embodiment, the terminal block defines at least one ventilation hole that fluidically connects the labyrinth seal to an upper surface of the terminal block.

[0028] According to one embodiment, the terminal block comprises a first part defining a plurality of grooves and a second part with a number of protrusions extending into the grooves to form a labyrinth seal.

[0029] According to one embodiment, the terminal block is attached to the wall using bolts.

[0030] According to one embodiment, the invention is further characterized by at least one motor in the first chamber, which is electrically connected to the plurality of connections.

[0031] According to one embodiment, the invention is further characterized by a power electronics module which is housed in the second chamber and is electrically connected to the plurality of terminals and is configured to provide power to the at least one motor.

[0032] According to the present invention, a terminal block is provided comprising: a non-conductive body having a first surface and a second surface; and a plurality of electrically conductive terminals extending through the body and projecting from the first surface and the second surface; wherein the body has a series of protrusions configured to interact with grooves of a counterpart to define a labyrinth seal that allows bidirectional air exchange between the first surface and the second surface while preventing fluid from flowing from the first surface to the second surface.

[0033] According to one embodiment, the non-conductive body defines at least one ventilation hole that fluidically connects the labyrinth seal to an upper surface of the non-conductive body.

[0034] According to one embodiment, the counterpart is a wall that separates two chambers of a housing of a gear assembly.

[0035] According to one embodiment, the invention is further characterized by the counterpart, wherein the counterpart is joined to the non-conductive body and both the non-conductive body and the counterpart are made of plastic.

[0036] According to one embodiment, the plurality of electrically conductive connections includes six connections.

Claims

[1] Hybrid transmission assembly comprising: a transmission housing defining a first chamber and a second chamber, the first and second chambers separated by a wall defining an opening; a terminal block attached to the wall and having a plurality of electrically 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 and second chambers while preventing fluid from flowing from the first chamber to the second chamber; at least one motor in the first chamber electrically connected to the plurality of terminals; and a power electronics module in the second chamber electrically connected to the plurality of terminals and configured to provide power to the at least one motor. [2] The hybrid transmission assembly of claim 1, wherein the wall defines a plurality of grooves at least partially surrounding the opening, and the port block includes a number of ridges extending into the grooves to form the labyrinth seal. [3] The hybrid transmission assembly of claim 2, wherein the port block defines at least one vent hole fluidly connecting the labyrinth seal to a top surface of the port 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 a second of the first chamber and the second chamber to the outside. [6] Hybrid transmission assembly comprising: a transmission housing defining a first chamber and a second chamber, the first and second chambers separated by a wall defining an opening; a terminal block attached to the wall and having a plurality of electrically conductive terminals extending through the opening, the terminal block and the wall being configured to allow bidirectional air exchange between the first and second chambers while preventing fluid from flowing from the first chamber to the second chamber; and a vent configured to allow airflow 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 the wall defines a plurality of grooves at least partially surrounding the opening, and the port block includes a number of ridges extending into the grooves to form a labyrinth seal. [8] The hybrid transmission assembly of claim 7, wherein the port block defines at least one vent hole fluidly connecting the labyrinth seal to a top surface of the port block. [9] The hybrid transmission assembly of claim 6, wherein the terminal block comprises a first portion defining a plurality of grooves and a second portion having a number of ridges extending into the grooves to form a labyrinth seal. [10] The hybrid transmission assembly of claim 6, wherein the terminal block is secured to the wall using bolts. [11] A hybrid transmission assembly according to claim 6, further comprising: at least one motor in the first chamber electrically connected to the plurality of terminals; and a power electronics module in the second chamber electrically connected to the plurality of terminals and configured to provide power to the at least one motor. [12] Terminal block, comprising: a non-conductive body having a first surface and a second surface; and a plurality of electrically conductive terminals extending through the body and projecting from the first surface and the second surface; wherein the body has a series of ridges configured to cooperate with grooves of a counterpart to define a labyrinth seal allowing bidirectional air exchange between the first surface and the second surface while preventing fluid 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 fluidly connecting the labyrinth seal to a top surface of the non-conductive body. [14] A terminal block according to claim 12, wherein the counterpart is a wall separating two chambers of a housing of a transmission assembly. [15] The terminal block of claim 12, further comprising the counterpart, wherein the counterpart is joined to the non-conductive body, and both the non-conductive body and the counterpart are made of plastic.

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