Patent Publication Number: US-2022216764-A1

Title: Baffle with integrated cooling for hybrid drive

Description:
TECHNICAL FIELD 
     The present disclosure relates to additional cooling for a hybrid drive module. 
     BACKGROUND 
     Power consumption by electric motors in hybrid drives generates heat. This is often dissipated by transmission fluid flows that act as a coolant, and fins may be provided to direct and/or interrupt the oil flow that can be on the hybrid drive module housing as well as a baffle sometimes used at an end of the module housing to separate wet and dry side components. However, depending on load requirements and the volume of air that passes over the hybrid drive module and the transmission, such as at idle speeds, insufficient cooling is provided. The excess heat can result in inefficient operation and/or damage to the motor windings. 
     A more efficient way of cooling the electric motor is required which does not expand or significantly change the current envelope for the hybrid drive module. 
     SUMMARY 
     The present disclosure provides a hybrid drive assembly having a hybrid drive housing with an electric motor and a disconnect clutch therein. A transmission is connected to the hybrid drive housing and a torque converter is provided between the electric motor and the transmission. A baffle extends radially between the torque converter and the hybrid drive housing. The baffle includes a ring-shaped body that is affixed to the hybrid drive housing and extends completely around a transmission side periphery of the hybrid drive housing. A fluid pathway is located on or in the baffle, and a plurality of orifices extend from the fluid pathway toward the electric motor. A fluid inlet port is connected to the fluid pathway. A fluid connection is provided from a pressurized fluid source to the fluid inlet port. This allows fluid, preferably transmission fluid circulated by a pump within the transmission, to be sprayed on the stator of the electric motor for cooling. The number and position of the orifices can be arranged to provide the desired coverage. 
     In one disclosed embodiment, the baffle includes an internal cavity in the ring-shaped body that forms the fluid pathway. The fluid pathway may extend at least about 120 degrees around the transmission side periphery of the hybrid drive housing, preferably in an upper region of the hybrid drive housing. 
     The baffle can be formed of a polymeric material and the internal cavity is preferably integrally formed in the baffle. The orifices are preferably arranged to spray fluid on stator windings of the electric motor. 
     In one arrangement, the baffle includes mounting tabs that are configured to be connected to mounting surfaces on the hybrid drive housing. The fluid inlet port can be located in one of the mounting tabs. 
     In another embodiment, the fluid pathway can be formed by a tube affixed to the baffle, and the orifices are formed in the tube. Here, the baffle can include clips that affix the tube to the baffle. The baffle can be formed of a polymeric material and the clips can be integrally formed on the baffle. 
     In one arrangement, the tube extends at least about 120 degrees around the transmission side periphery of the hybrid drive housing. 
     The tube can be Y-shaped, and the center leg of the Y-shape can include the fluid inlet port which is connected to the pressurized fluid source. Here again, the orifices are adapted to spray fluid on stator windings of the electric motor. 
     In either arrangement, a number and location of the orifices is selected based on a desired cooling area. 
     In another aspect, a baffle having integrated cooling channels for a hybrid drive assembly is provided and has a ring-shaped body that is adapted to be affixed to a hybrid drive housing and extend completely around a transmission side periphery of the hybrid drive housing. A fluid pathway is located on or in the baffle, and a plurality of orifices extend from the fluid pathway that are configured to be oriented toward an electric motor of the hybrid drive assembly. A fluid inlet port is connected to the fluid pathway. 
     In one embodiment, the baffle includes an internal cavity that forms the fluid pathway that extends at least about 120 degrees around the ring-shaped body. The baffle can be formed of a polymeric material and the internal cavity can be integrally formed in the baffle. 
     In another embodiment, the fluid pathway can be formed by a tube affixed to the ring-shaped body, and the orifices are formed in the tube. Here, the ring-shaped body can include clips that affix the tube to the baffle. 
     Additional embodiments described below and in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing Summary and the following Detailed Description will be better understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the disclosure. In the drawings: 
         FIG. 1  is a cross-sectional view through a portion of a hybrid drive assembly for a motor vehicle, shown in half-section. 
         FIG. 2  is a front view of a baffle having a fluid pathway for cooling the electric motor of the hybrid drive assembly. 
         FIG. 3  is a perspective view of a second embodiment of a baffle connected around a transmission side periphery of a hybrid drive housing of a hybrid drive assembly for a motor vehicle. 
         FIG. 4  is a front view of the baffle shown in  FIG. 3 . 
         FIG. 5  is a cross-section view through the baffle shown in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     Certain terminology is used in the following description for convenience only and is not limiting. The words “front,” “rear,” “upper” and “lower” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from the parts referenced in the drawings. “Axially” refers to a direction along the axis of a shaft. A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof. This terminology includes the words specifically noted above, derivatives thereof and words of similar import. “Generally” or “approximately” refers to +/−10% of the indicated value. 
     The term e-machine is used generally herein to refer to an electric motor, such as a motor including a rotor, stator with windings, resolver, etc., used here in connection with a hybrid drive system. 
     Referring to  FIG. 1 , a hybrid drive assembly  10  is shown in a half cross-section. The hybrid drive assembly  10  is adapted to be connected to the output of an internal combustion engine and is located between the engine and the transmission. The hybrid drive assembly  10  includes a hybrid drive housing  12  with an electric motor  14  and a disconnect clutch  20  located therein. The electric motor  14  includes a stator  16  and a rotor  18 , with the rotor  18  being detachably connectable via an input shaft  23  to a torque converter  24  via the disconnect clutch  20 . A transmission  22  is connected to the hybrid drive housing  12 , with the torque converter  24  being located in the torque transmission path between the electric motor  14  and the transmission  22 . 
     A baffle  30  extends radially between the torque converter  24  and the hybrid drive housing  12 . The baffle  30  includes a ring-shaped body  32 , best shown in  FIG. 2 , and is affixed to the hybrid drive housing  12 , preferably via mounting tabs  36  that are configured to be connected to the mounting surfaces  13  on the hybrid drive housing  12 . Hook-shaped engagement surfaces  33  can also be provided that engage with an edge of the electric motor  14 , preferably with an edge of the stator  16 . As shown in  FIG. 2 , preferably three of the mounting tabs  36  are provided; however, the number of tabs could be varied. Bolt holes  37  can be provided in the mounting tabs. Additionally, the number of mounting surfaces  13  required on the hybrid drive housing  12  is configured accordingly. 
     Still with reference to  FIGS. 1 and 2 , the ring-shaped body  32  extends completely around a transmission side periphery of the hybrid drive housing  12 . This arrangement makes the baffle  30  more robust and streamlined, plus allows for more secure positioning. As shown in  FIG. 2 , one or more fins  39  can be provided in the baffle  30  that are used to help direct and/or interrupt a flow of fluid in the transmission. 
     Still with reference to  FIGS. 1 and 2 , a fluid pathway  40  is located on or in the baffle  30 . A plurality of offices  42  extend from the fluid pathway  40  toward the electric motor  14 . A fluid inlet port  44 , preferably located in one of the mounting tabs  36 , is connected to the fluid pathway  40 . As shown in  FIG. 1 , a fluid connection from a pressurized fluid source  46  is provided to the fluid inlet port  44 . 
     As shown in  FIGS. 1 and 2 , in this embodiment, the baffle  30  includes an internal cavity  34  in the ring-shaped body  32  that forms the fluid pathway  40 . The fluid pathway  40  preferably extends at least about 120° around the transmission side periphery of the hybrid drive housing  12 . However, it could extend a greater or lesser amount, for example between 90° and 180°, or could extend around the entire periphery. 
     The baffle  30  may be formed of a polymeric material and the internal cavity  34  can be integrally formed in the baffle  30 . As shown in  FIGS. 1 and 2 , the orifices  42  are adapted to spray fluid on the electric motor  14 , preferably on the stator  16 . As gravity will carry the fluid downwardly, it is only necessary to have orifices in an upper portion of the baffle  30  for some applications, depending upon the cooling load that is being dissipated. The fluid is preferably transmission fluid that is circulated by a fluid pump in the transmission  22 . 
     As shown in  FIG. 2 , the fluid inlet port  44  can be located in one of the mounting tabs  36 . Seals can be provided, as would be understood by a person of ordinary skill in the art based on the present disclosure. 
     In order to provide sufficient cooling, the number and location of the orifices  42  can be selected in order to achieve a desired cooling area for the electric motor  14 . 
     Referring now to  FIGS. 3-5 , an alternate embodiment of the baffle  30 ′ is shown for use in connection with the hybrid drive assembly  10 . The baffle  30 ′ has a ring-shaped body  32 ′ and is arranged in the same manner as the baffle  30 ; however, the fluid pathway  40  is formed by a tube  48  that is affixed to the baffle  30 ′. The orifices  42  are formed in the tube  48 . 
     As shown in  FIGS. 3-5 , the baffle  30 ′ includes clips  38  that affix the tube  48  to the baffle  30 ′. The baffle  30 ′ may also be formed of a polymeric material and the clips  38  can be integrally formed on the baffle  30 ′. Alternatively, the clips  38  could be separately attached. 
     As shown in detail in  FIGS. 3 and 4 , the tube  48  is preferably Y-shaped, and the center leg of the Y-shape includes the fluid inlet port  44  which is connected to the pressurized fluid source  46 . Here, an O-ring is used as a seal on the center leg of the tube  48 . 
     While the tube  48  is only shown extending approximately 120° around the transmission side periphery of the hybrid drive housing  12 , a person of ordinary skill in the art will recognize from the present disclosure that the tube could extend a greater or lesser amount around the periphery as noted above, depending upon the cooling load of the particular hybrid drive assembly  10 . 
     The baffles  30 ,  30 ′ with the fluid pathway  40  for cooling the hybrid drive assembly are preferably produced as separate parts and each includes a ring-shaped body  32 ,  32 ′ that is adapted to be fixed to the hybrid drive housing  12  and extend completely around the transmission side periphery of the hybrid drive housing  12  in order to provide a more robust design with enhanced structural integrity. As discussed above, the fluid pathway  40  can either be provided integrally by an internal cavity  34  within the baffle  30  or via a separate tube  48  affixed to the baffle  30 ′. In either case, the baffle  30 ,  30 ′ is preferably formed of a polymeric material and may include fins  39 , one of which is indicated in  FIG. 2 , that may be used to direct a flow and/or interrupt undesired flow of oil in the transmission. This reduces losses in the system and ensures all the oil is making it back the sump. 
     Having thus described the present embodiments in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the disclosure, could be made without altering the inventive concepts and principles embodied therein. 
     It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. 
     The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the disclosure being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein. 
     LOG OF REFERENCE NUMERALS 
     
         
         
           
               10  hybrid drive assembly 
               12  hybrid drive housing 
               13  mounting surfaces 
               14  electric motor 
               16  stator 
               18  rotor 
               20  disconnect clutch 
               22  transmission 
               24  torque converter 
               30 ,  30 ′ baffle 
               32 ,  32 ′ ring-shaped body 
               33  hook-shaped engagement 
               34  internal cavity 
               36  mounting tabs 
               37  bolt holes 
               38  clips 
               39  fin 
               40  fluid pathway 
               42  orifices 
               44  fluid inlet port 
               46  pressurized fluid source 
               48  tube