Abstract:
An improved hybrid electro-mechanical vehicular transmission includes motor/generator modules assembled from like components. This is accomplished by providing “punch-out” tabs on the motor/generator module housing enabling the housing to be used on either the first or second motor/generator module within a hybrid electro-mechanical vehicular transmission, thus enabling like components to be used within both the first and second motor/generator module.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/555,141, filed Mar. 22, 2004, which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a hybrid electro-mechanical vehicular transmission having motor/generator modules assembled from like components. 
     BACKGROUND OF THE INVENTION 
     Dual motor hybrid electro-mechanical vehicular transmissions have traditionally used non-modular motor/generator units with separate and independent electrical wiring connections for each motor. In an effort to increase production line efficiency and product quality, auto manufacturers have adopted modular assembly processes. This type of process allows part assemblies to be manufactured and tested off-site and subsequently shipped to the assembly plant where the modular assemblies are installed. An additional philosophy that is often employed in manufacturing is economies of scale. The basic premise of economies of scale is that production on a large scale may result in a lower piece cost. For this reason, manufacturers strive to use the like parts within different modules or part assemblies. By using like parts within different part assemblies, a lower piece cost may be achieved, piece quality may improve, and part confusion may diminish. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved hybrid electro-mechanical vehicular transmission having motor/generator modules assembled from like components. This is accomplished by providing “punch-out” tabs on the motor/generator module housing enabling the housing to be used on either the first or second motor/generator module within a hybrid electro-mechanical vehicular transmission, thus enabling like components to be used within both the first and second motor/generator module. 
     By reducing the number of components that are unique to the first and second motor/generator module, the cost, complexity, assembly time, spatial “footprint”, and part confusion may be reduced, while part quality may increase. 
     Accordingly, the present invention provides a hybrid electro-mechanical vehicular transmission having a transmission main housing configured to receive a plurality of motor/generator modules. Each motor/generator module includes an electric motor/generator having a stator and rotor assembly and an electrical connector in electrical communication with the motor/generator. Also provided is a drum having a module housing operable to contain one of the electric motors and a module cover positioned at an open end of the module housing and to provide attachment to the transmission main housing. Additionally, the present invention provides a plurality of “punch-out” tabs formed integrally with the module housing and operable to create windows through which the electrical connections may pass. The plurality of “punch-out” tabs are operable to position and stabilize the electrical connector. 
     The module housing may be formed by flow forming and the module cover may be formed by stamping. The module cover may have three mounting members radially spaced at 120 degree increments on the periphery of the module cover and operable to mount each of the motor/generators, which may number two, within the transmission main housing. 
     Additionally, each of the plurality of motor/generator modules may have a plurality of lubrication and cooling inlet ports and at least one lubrication and cooling exhaust port centered at top dead center and bottom dead center of the motor/generator module respectively. 
     Yet another aspect of the present invention is a hybrid electro-mechanical vehicular transmission having a transmission main housing with a first and second module side to receive respectively one of two motor/generator modules. Each of the motor/generator modules include an electric motor/generator having a stator and rotor assembly and an electrical connection in electrical communication with the motor/generator. Also provided is a drum defining a module housing containing the motor/generator and having a module cover portion. The module cover portion is configured with a mounting pattern that aligns differently in the main housing with the electrical connection of one module with respect to the first module side of the main housing than with the electrical connection of the other module with respect to the second side of the main housing. This will ensure that only one module can be placed in the first module side of the main housing and only the other module can be placed in the second module side of the main housing. 
     The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic cross-sectional view of a hybrid electro-mechanical vehicular transmission having a first (A) and a second (B) motor/generator module; 
         FIG. 2  is a left side perspective view of a first (A) and a second (B) motor/generator module illustrating the preferred orientation when placed within the hybrid electro-mechanical vehicular transmission; 
         FIG. 3  is a rear perspective view of a drum illustrating the module housing having “punch-out” tabs consistent with the present invention; and 
         FIG. 4  is a fragmentary exploded view of a hybrid electro-mechanical vehicular transmission illustrating the placement of the second (B) motor/generator module therein as well as the main housing power wire openings. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In  FIG. 1  there is shown a side elevational sectional view of a hybrid electro-mechanical vehicular transmission  10  having a first motor/generator module A, and a second motor/generator module B. The motor/generator modules A and B may be operated in various modes to accelerate and drive the vehicle, start the engine, brake the vehicle, and charge the batteries (not shown). Each of the motor/generator modules A and B include a motor/generator  12 A and  12 B respectively each having a stator  14 A and  14 B circumscribing a rotor  16 A and  16 B. The motor/generator modules A and B also include motor/generator power connectors  18 A and  18 B and motor/generator position and speed sensors  20 A and  20 B. A drum  21 A and  21 B defines a module housing  22 A and  22 B which is operable to contain the stator  14 A and  14 B, rotor  16 A and  16 B, motor/generator power connection  18 A and  18 B, and the motor/generator position and speed sensor  20 A and  20 B for each of the first motor/generator module A and the second motor/generator module B. In the preferred embodiment, the module housing  22 A and  22 B will be flow formed. A module cover  24 A and  24 B cooperates with the module housing  22 A and  22 B to contain the elements therein. In the preferred embodiment, the module cover  24 A and  24 B will be stamped from metal sheet stock. 
     In  FIG. 2  there is shown a side perspective view of the first motor/generator module A and the second motor/generator module B, illustrating the preferred orientation when placed within the hybrid electro-mechanical vehicular transmission  10 . The motor/generator modules A and B are each lubricated and cooled by a bath of transmission fluid passing through a plurality of lubrication and cooling inlet ports  30 A and  30 B formed within, and centered about the top dead center of the drum  21 A and  21 B respectively. The transmission fluid subsequently passes over the stator  14 A and  14 B and rotor  16 A and  16 B and carries the rejected heat energy through the lubrication and cooling exhaust ports  32 A and  32 B centered about bottom dead center of the drum  21 A and  21 B. 
     Referring again to  FIG. 1 , the motor/generator modules A and B are distinct orientations of like components. While the motor/generator modules A and B face opposite directions (i.e., they are mirror images of one another about a vertical centerline  26 ), it is preferred that they provide access for a common transmission electrical terminal assembly  28  to the motor/generator power connections  18 A and  18 B on a common side of the hybrid electro-mechanical vehicular transmission  10 . Such alignment is typically not achievable with identical motor/generator modules. The first motor/generator module A cannot be rotated about the vertical centerline  26 , and subsequently “clocked” (i.e., partially rotated about the central axis of the hybrid electro-mechanical vehicular transmission  10 ) such that the motor/generator power connection  18 A is in the proper orientation to create the second motor/generator module B, as shown in  FIG. 2 . This action is proscribed by the need to maintain the plurality of lubrication and cooling inlet ports  30 A centered about the top dead center of the drum  21 A, and the desire to maintain the lubrication and cooling exhaust ports  32 A centered about bottom dead center of the drum  21 A. 
     As shown in  FIG. 3 , the present invention provides module housings  22  each having two “punch-out” tabs  36  and  36 ′. These “punch-out” tabs  36  and  36 ′ are formed during the forming process of the module housing  22 . When the “punch-out” tab  36  is formed, a first window  38  is created through which motor/generator power connections  18 A will pass. Alternately, when the “punch-out” tab  36 ′ is formed, a second window  40  is created through which motor/generator power connections  18 B (shown in  FIG. 2 ) will pass. 
     The “punch-out” tabs  36  and  36 ′ function to locate and stabilize the motor/generator power connectors  18 A and  18 B during connection to the electrical terminal assembly  28  (shown in  FIG. 1 ). 
     The first window  38  is disposed above the horizontal axis line  42 , and the second window  40  is disposed below the horizontal axis line  42 , with the first window  38  and second window  40  radially centered opposite one another in the module housing  22  along line  44 . 
     By employing “punch-out” tabs  36  and  36 ′ in such a way, the proper orientation for the lubrication and cooling inlet ports  30 A and  30 B and the lubrication and cooling outlet ports  32 A and  32 B may be maintained regardless of whether motor/generator power connections  18  passes through first window  38  or second window  40 . Accordingly, the window through which the motor/generator power connections  18  passes will determine whether a first motor/generator module A is created or a second motor/generator module B is created. 
     In addition, the module housing  22  defines two sensor wiring windows  46 A and  46 B to enable electrical connection between the transmission control module (not shown) and the motor/generator position and speed sensors  20 A and  20 B. The sensor wiring windows  46 A and  46 B are positioned incongruently, such that after the first motor/generator module A and the second motor/generator module B are positioned within the hybrid electro-mechanical vehicular transmission  10 , the sensor wiring windows  46 A and  46 B provide non-adjacent locations for wiring connector  48 A and  48 B (shown in  FIG. 2 ). The wiring connectors  48 A and  48 B are the terminal ends leading form the motor/generator position and speed sensors  20 A and  20 B respectively. Therefore, the connections to the wiring connectors  48 A and  48 B may be error-proofed by utilizing differing wiring harness (not shown) lead lengths. 
     Referring to  FIG. 4 , the module cover  24 B provides three mounting members  50 , spaced at 120 degree intervals, for bolting the motor/generator module B to the transmission main housing  52 . Likewise, as shown in  FIG. 2 and 3 , the module cover  24 A provides three mounting members  50 , spaced at 120 degree intervals, for bolting the motor/generator module A to the transmission main housing  52 . The transmission main housing  52  has mounting cavities  54  for receiving the module cover mounting members  50 . Additionally, module connection openings  56 A and  56 B, defined by the main transmission housing  52 , are spaced in such a way to provide clearance for the motor/generator power connections  18 A and  18 B. The 120° pattern of the mounting cavities  54  align differently in the transmission main housing  52  with the first and the second main housing power wire openings  56 A and  56 B, such that only a first motor/generator module A can be placed in the first module side  57  of the main transmission housing  52 . Accordingly, only a second motor/generator module can be placed in the second module side  58  of the transmission main housing  52 , thus providing additional assembly error proofing. Although like components are used for both motor/generator modules A and B, unique positioning features differentiate the first motor/generator module A from the second motor/generator module B. 
     By reducing the number of components that are unique to the first and second motor/generator module A and B, the cost, complexity, assembly time, spatial “footprint”, and part confusion may be reduced, while part quality may increase. 
     While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.