Patent Publication Number: US-2022227216-A1

Title: Modular transmission mechanism for hybrid power system, and hybrid power system

Description:
TECHNICAL FIELD 
     The present invention relates to a hybrid vehicle and, in particular, to a modular transmission mechanism for a hybrid power system of a vehicle and a hybrid power system comprising the transmission mechanism. 
     BACKGROUND 
     At present, in an existing dual-motor hybrid power system for a vehicle, dual motors are usually arranged in different positions of the hybrid power system, such that the hybrid power system implements different architectures. 
     As shown in  FIG. 1 a   , in a dual-motor hybrid power system, an output shaft of an engine ICE is directly connected to an input/output shaft of a first motor EM 1 , the input/output shaft of the first motor EM 1  can be in drive coupling with an input shaft of a transmission DHT via engagement of a clutch K 0 , and an input/output shaft of a second motor EM 2  is in drive coupling with an output shaft of the transmission DHT via a gear pair. In this way, the hybrid power system has a P1 architecture (corresponding to a position of the first motor EM 1 ) and a P3 architecture (corresponding to a position of the second motor EM 2 ). 
     As shown in  FIG. 1 b   , in another dual-motor hybrid power system, an output shaft of an engine ICE can be in drive coupling with an input/output shaft of a first motor EM 1  via engagement of a clutch K 0 , the input/output shaft of the first motor EM 1  is directly connected to the input shaft of the transmission DHT, and the input/output shaft of the second motor EM 2  is in drive coupling with the output shaft of the transmission DHT via the gear pair. In this way, the hybrid power system implements a P2 architecture (corresponding to a position of the first motor EM 1 ) and a P3 architecture (corresponding to a position of the second motor EM 2 ). 
     In the above-mentioned two commonly-used dual-motor hybrid power systems, given that the first motor EM 1  is arranged in different positions, it is usually necessary to separately design a power transmission mechanism corresponding to the P1 architecture and the P2 architecture, which greatly adds to the research and development cost and burden. 
     SUMMARY 
     The present invention has been made in view of the deficiencies of the prior art as described above. An object of the present invention is to provide a novel modular transmission mechanism for a hybrid power system. The modular transmission mechanism can easily implement a P1 architecture and a P2 architecture in the hybrid power system, thereby reducing the research and development cost and burden consumed by separate development in the above-mentioned prior art. Another object of the present invention is to provide a hybrid power system comprising the modular transmission mechanism. 
     To achieve the above-mentioned objects, the present invention adopts the following technical solutions. 
     The present invention provides a modular transmission mechanism for a hybrid power system as follows, comprising: 
     a motor comprising a stator and a rotor located on a radial inside of the stator and capable of rotating relative to the stator; 
     a rotor support assembly fixedly connected to the rotor and located on a radial inside of the rotor; 
     a clutch located on the radial inside of the rotor and comprising a plurality of pressure plates, a plurality of friction disks, and an input/output bracket, wherein the plurality of pressure plates are capable of engaging the plurality of friction disks to enable the rotor support assembly to be in drive coupling with the input/output bracket; 
     a concentric slave cylinder integrally fixed relative to the stator and comprising a piston, wherein the piston is capable of exerting pressure to the pressure plate to enable the plurality of friction disks to be engaged with one another; 
     an engine output shaft located on radial insides of both the concentric slave cylinder and the rotor support assembly; and 
     an output assembly, 
     wherein the engine output shaft is connected to the input/output bracket and the output assembly is connected to the rotor support assembly; or 
     the engine output shaft is connected to the rotor support assembly and the output assembly is connected to the input/output bracket. 
     Preferably, the rotor support assembly comprises a rotor bracket and a rotor flange, the rotor bracket is fixedly connected to the rotor, the rotor flange is located on a radial inside of the rotor bracket and is fixedly connected to the rotor bracket, and the clutch is located between the rotor bracket and the rotor flange. 
     More preferably, the rotor flange comprises a rotor flange radial portion extending in a radial direction and a rotor flange axial portion extending from a radial inside end of the rotor flange radial portion toward one axial side, the clutch is located on a radial outside of the rotor flange axial portion, and the plurality of pressure plates are in drive coupling with the rotor flange axial portion in a circumferential direction. 
     More preferably, the rotor flange axial portion is further provided with an axial stopper, and the axial stopper is located in a position on one axial side of the pressure plate closest to one axial side among the plurality of pressure plates. 
     More preferably, the mass of at least one pressure plate located at the center among the plurality of pressure plates is greater than that of the other pressure plates. 
     More preferably, a part of a cylinder body of the concentric slave cylinder is located on the radial inside of the rotor flange axial portion, and the modular transmission mechanism comprises at least one bearing located between the rotor flange axial portion and the cylinder body and at least two bearings located between the cylinder body and the engine output shaft. 
     More preferably, the modular transmission mechanism further comprises a housing, wherein the housing is fixed relative to an engine of the hybrid power system, the housing comprises a housing radial portion extending in a radial direction, and a first housing axial portion and a second housing axial portion extending from a radial outside end of the housing radial portion toward the other axial side and one axial side, respectively, and 
     the cylinder body of the concentric slave cylinder is fixed on the housing radial portion and the motor is located on a radial inside of the second housing axial portion. 
     More preferably, the modular transmission mechanism further comprises a cooling jacket, wherein the cooling jacket is located on the radial inside of the second housing axial portion and fixed to the second housing axial portion, and the stator is located on a radial inside of the cooling jacket and fixed to the cooling jacket. 
     The present invention further provides a hybrid power system as follows, comprising: 
     an engine in drive coupling with the engine output shaft; 
     a transmission comprising a transmission input shaft; and 
     the modular transmission mechanism for a hybrid power system according to any one of the above-mentioned technical solutions, 
     wherein the engine output shaft is fixedly connected to the input/output bracket, and the rotor support assembly is in drive coupling with the transmission input shaft via the output assembly. 
     The present invention further provides a hybrid power system as follows, comprising: 
     an engine in drive coupling with the engine output shaft; 
     a transmission comprising a transmission input shaft; and 
     the modular transmission mechanism for a hybrid power system according to any one of the above-mentioned technical solutions, 
     wherein the engine output shaft is fixedly connected to the rotor support assembly, and the input/output bracket is in drive coupling with the transmission input shaft via the output assembly. 
     By adopting the above-mentioned technical solutions, the present invention provides a novel modular transmission mechanism for a hybrid power system, and a hybrid power system comprising the modular transmission mechanism. The modular transmission mechanism integrates a motor, a rotor support assembly, a clutch, a concentric slave cylinder, and an engine output shaft. On the one hand, the modular transmission mechanism enables an input/output bracket of the clutch to be in drive coupling with the engine output shaft, and the rotor support assembly to be in drive coupling with an input shaft of a transmission; on the other hand, the modular transmission mechanism enables the input/output bracket of the clutch to be in drive coupling with the input shaft of the transmission, and the rotor support assembly to be in drive coupling with the engine output shaft. In this way, the modular transmission mechanism according to the present invention can realize a conversion of the hybrid power system between a P1 architecture and a P2 architecture only by simple adjustment on the structure, thereby reducing the research and development cost and burden consumed by separately developing the P1 architecture and the P2 architecture. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1 a    is a schematic diagram illustrating a topological connection structure of a dual-motor hybrid power system in the prior art, wherein the hybrid power system has a P1 architecture and a P3 architecture; and  FIG. 1 b    is a schematic diagram illustrating a topological connection structure of another dual-motor hybrid power system in the prior art, wherein the hybrid power system has a P2 architecture and a P3 architecture. 
         FIG. 2  is a schematic partial structural diagram illustrating the implementation of a hybrid power system with a P2 architecture by using a modular transmission mechanism according to the present invention, wherein the structure of the modular transmission mechanism according to the present invention is mainly illustrated in the form of a sectional view, and section lines of each component are omitted. 
         FIG. 3  is a schematic partial structural diagram illustrating the implementation of a hybrid power system with a P1 architecture by using a modular transmission mechanism according to the present invention, wherein the structure of the modular transmission mechanism according to the present invention is mainly illustrated in the form of a sectional view, and section lines of each component are omitted. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of the present invention will be described below with reference to the drawings. It should be noted that in the present invention, “axial direction”, “radial direction” and “circumferential direction” refer to an axial direction, a radial direction and a circumferential direction of an engine output shaft, respectively. “One axial side” refers to the right side in  FIG. 2  and  FIG. 3 , “the other axial side” refers to the left side in  FIG. 2  and  FIG. 3 , “radial outside” refers to the upper side in  FIG. 2  and  FIG. 3  (i.e., the side away from a central axis O), and “radial inside” refers to the lower side in  FIG. 2  and  FIG. 3  (i.e., the side close to the central axis O). 
     A hybrid power system with a P2 architecture implemented by using a modular transmission mechanism for a hybrid power system according to the present invention will be described below first. 
     (Hybrid Power System with the P2 Architecture) 
     The hybrid power system with the P2 architecture according to the present invention comprises a modular transmission mechanism for a hybrid power system according to the present invention, an engine (not shown), a transmission (not shown), and the like. 
     As shown in  FIG. 2 , the modular transmission mechanism for a hybrid power system comprises a housing  1 , a cooling jacket  2 , a motor  3 , a rotor support assembly  4 , a clutch  5 , a concentric slave cylinder  6 , an engine output shaft  7 , a shock absorber  8  and an output assembly  9  that are assembled together, and all the above-mentioned components are assembled together in a coaxial manner. 
     Specifically, the housing  1  of the modular transmission mechanism is fixed to an engine body or a transmission housing by, for example, a bolt, such that the housing  1  is fixed relative to the engine and the transmission of the hybrid power system. 
     The housing  1  comprises a housing radial portion  11 , a first housing axial portion  12  and a second housing axial portion  13  that are integrally formed. The housing radial portion  11  extends roughly in a radial direction R, and the first housing axial portion  12  and the second housing axial portion  13  extend from a radial outside end of the housing radial portion  11  toward the other axial side and one axial side in an axial direction A, respectively, such that a space entirely surrounded by the first housing axial portion  12  and the second housing axial portion  13  is partitioned by the housing radial portion  11  into two parts. 
     Furthermore, the cooling jacket  2  is located on a radial inside of the second housing axial portion  13  and fixed to the second housing axial portion  13 , and a flow channel for a cooling liquid (such as water) is formed between the cooling jacket  2  and the second housing axial portion  13  to enable the cooling jacket  2  to cool a stator  31  of the motor  3 . In addition, the cooling jacket  2  can further support the stator  31 . 
     Furthermore, the motor  3  comprises the stator  31  and a rotor  32  located on a radial inside of the stator  31  and capable of rotating relative to the stator  31 . The stator  31  is located on a radial inside of the cooling jacket  2  and fixed to the cooling jacket  2 , and the rotor  32  can rotate relative to the stator  31  in a magnetic field generated by the stator  31 , thereby outputting a driving force/torque. 
     Furthermore, the rotor support assembly  4  is fixedly connected to the rotor  32  and located on a radial inside of the rotor  32 , and the rotor support assembly  4  is configured to transmit the driving force/torque from the rotor  32  while supporting the rotor  32  from the radial inside. Specifically, the rotor support assembly  4  comprises a rotor bracket  41  and a rotor flange  42  that are fixed to each other. 
     The rotor bracket  41  is located on the radial inside of the rotor  32 . The rotor bracket  41  is directly and fixedly connected to the rotor  32  through, for example, interference fit, and the rotor bracket  41  is configured to support the rotor  32 . 
     The rotor flange  42  is located on a radial inside of the rotor bracket  41  and fixedly connected to the rotor bracket  41 , such that the rotor flange  42  can support the rotor bracket  41  and the rotor  32 . The rotor flange  42  comprises a rotor flange radial portion  421  extending in the radial direction and a rotor flange axial portion  422  extending from a radial inside end of the rotor flange radial portion  421  toward one axial side. A radial outside end of the rotor flange radial portion  421  is fixedly connected to the rotor bracket  41 . The rotor flange axial portion  422  overlaps the rotor bracket  41  in the axial direction A, such that the rotor bracket  41 , the rotor flange radial portion  421  and the rotor flange axial portion  422  surround and form an installation space for the clutch  5 . 
     In addition, the rotor flange axial portion  422  is further provided with an axial stopper  423  configured to axially position the clutch  5 . 
     Furthermore, the clutch  5  is located between the rotor bracket  41  and the rotor flange  42 , and is specifically installed in the above-mentioned installation space surrounded and formed by the rotor bracket  41 , the rotor flange radial portion  421  and the rotor flange axial portion  422 . Therefore, the clutch  5  is located on one axial side of the rotor flange radial portion  421  and on a radial outside of the rotor flange axial portion  422 . 
     The clutch  5  comprises three pressure plates parallel to and spaced from one another (a first pressure plate  51   a  located on the other axial side, a third pressure plate  51   c  located on one axial side and a second pressure plate  51   b  located between the first pressure plate  51   a  and the third pressure plate  51   c ), a plurality of friction disks  52 , and an input/output bracket  53 . The plurality of friction disks  52  are located between the three pressure plates  51   a ,  51   b  and  51   c . Preferably, some friction disks  52  of the plurality of friction disks  52  are fixed to the pressure plates  51   a ,  51   b  and  51   c , and the other friction disks  52  are fixed to the input/output bracket  53 . The three pressure plates  51   a ,  51   b  and  51   c  enable the plurality of friction disks  52  to be in drive coupling/uncoupling with one another. Furthermore, preferably, the friction disks  52  fixed to the input/output bracket  53  are double-sided friction disks. The three pressure plates  51   a ,  51   b  and  51   c  are further always in drive coupling with the rotor support assembly  4  in a circumferential direction, specifically, the three pressure plates  51   a ,  51   b  and  51   c  are always in drive coupling with the rotor flange axial portion  422  through splines. The axial stopper  423  arranged on the rotor flange axial portion  422  is located in a position on one axial side of the third pressure plate  51   c  closest to one axial side among the three pressure plates  51   a ,  51   b  and  51   c , so as to axially limit the clutch  5  from one axial side. Since the three pressure plates  51   a ,  51   b  and  51   c  are in drive coupling with the rotor flange  42  instead of being directly connected to the rotor bracket  41 , heat generated by the clutch  5  is prevented from being directly transferred to the rotor  32 , and thus the influence of the heat generated by the clutch  5  on the rotor  32  is very slight. 
     In addition, among the three pressure plates  51   a ,  51   b  and  51   c , the mass of the second pressure plate  51   b  is much greater than that of the first pressure plate  51   a  and that of the third pressure plate  51   c , such that the heat capacity of the whole clutch  5  is improved. 
     Furthermore, the concentric slave cylinder  6  comprises a cylinder body  61  fixed to a radial inside end of the housing radial portion  11 , a modular clutch actuator  62 , a release bearing  63 , and a piston  64 . 
     One part of the cylinder body  61  of the concentric slave cylinder  6  extends from the radial inside end of the housing radial portion  11  toward the radial inside roughly in the radial direction R, and the other part of the cylinder body  61  extends from the radial inside end of the above-mentioned part toward one axial side in the axial direction A, such that the other part of the cylinder body  61  is located on a radial inside of the rotor flange axial portion  422  and overlaps the rotor flange axial portion  422  in the axial direction A. 
     The modular clutch actuator  62  is arranged in the housing  1 , and by controlling high-pressure oil, the modular clutch actuator  62  enables the release bearing  63  to exert or cancel an axial pressure on the piston  64 , so as to control the engagement/disengagement of the clutch  5 . The modular clutch actuator  62  has the same structure as similar mechanisms in the prior art, and thus will not be described in detail in the present specification. 
     An inner ring of the release bearing  63  abuts against the modular clutch actuator  62  in the axial direction A, and an outer ring of the release bearing  63  abuts against the piston  64  in the axial direction A, such that the release bearing  63  can successfully transmit the axial pressure from the modular clutch actuator  62  to the piston  64 . 
     One part of the piston  64  is for the outer ring of the release bearing  63  to abut against, and the other part thereof passes through a through hole formed in the rotor flange radial portion  421  and presses against the first pressure plate  51   a  from the other axial side, such that the piston  64  can cooperate with the axial stopper  423  arranged on the rotor flange axial portion  422  to axially limit the clutch  5 . 
     In this way, when the release bearing  63  is driven by the modular clutch actuator  62  to exert the axial pressure to the piston  64  toward one axial side, the piston  64  exerts pressure to the first pressure plate  51   a  toward one axial side until the plurality of friction disks  52  between the three pressure plates  51   a ,  51   b  and  51   c  are fully engaged with one another, such that the clutch  5  is engaged; when the release bearing  63  cancels the above-mentioned axial pressure exerted to the piston  64 , the friction disks  52  between the three pressure plates  51   a ,  51   b  and  51   c  can be disengaged from one another under the action of, for example, a return spring (not shown), such that the clutch  5  is disengaged. 
     Furthermore, the engine output shaft  7  is located on radial insides of both the concentric slave cylinder  6  and the rotor support assembly  4 . The engine output shaft  7  comprises a shaft portion  71  linearly extending in the axial direction A and a central flange  72  fixed to one axial end of the shaft portion  71 , and the central flange  72  extends in the radial direction R. A radial outside end of the central flange  72  is fixed to the input/output bracket  53  of the clutch  5 . 
     Furthermore, the shock absorber  8  is fixed to the other axial end of the shaft portion  71  of the engine output shaft  7 , and the shock absorber  8  is located on the other axial side of the housing radial portion  11  and the other axial side of the concentric slave cylinder  6  and located on a radial inside of the first housing axial portion  12 ; and the shock absorber  8  is configured to attenuate torsional vibration of the engine such that a driving force/torque from the engine can be transmitted to the engine output shaft  7  as steadily as possible. 
     Furthermore, the output assembly  9  comprises a flexible plate  91  and a hub core  92  of the flexible plate that are connected to each other. A radial outside end of the flexible plate  91  is fixed to the rotor bracket  41  through, for example, a screw, and a radial inside end of the flexible plate  91  is fixed to the hub core  92  of the flexible plate. The hub core  92  of the flexible plate is configured to be in drive coupling with an input shaft of the transmission. 
     In addition, in order to ensure that the rotor flange  42  is rotatably supported by the cylinder body  61  relative to the cylinder body  61  of the concentric slave cylinder  6 , the modular transmission mechanism comprises a bearing (double-row ball bearing) B 1  located between the rotor flange axial portion  422  and the cylinder body  61 . Similarly, in order to ensure that the cylinder body  61  of the concentric slave cylinder  6  is rotatably supported by the engine output shaft  7  relative to the engine output shaft  7 , the modular transmission mechanism comprises two bearings (a single-row deep groove ball bearing and a needle bearing) B 3  and B 2  located between the cylinder body  61  and the engine output shaft  7 . Outer rings and inner rings of the above-mentioned bearings are all axially limited by appropriate structures. 
     In this way, in the hybrid power system with the P2 architecture shown in  FIG. 2 , 
     on the one hand, the engine output shaft  7  of the modular transmission mechanism is in drive coupling with a crankshaft of the engine, such that the driving force/torque from the engine can be transmitted to the engine output shaft  7 , and the engine output shaft  7  is further fixedly connected to the input/output bracket  53  of the clutch  5 , such that the driving force/torque from the engine output shaft  7  can be directly transmitted to the rotor support assembly  4  when the clutch  5  is engaged; and 
     on the other hand, the rotor support assembly  4  is fixedly connected to the rotor  32 , such that the driving force/torque from the rotor  32  of the motor  3  can be directly transmitted to the rotor support assembly  4 , such that the driving force/torque from the engine output shaft  7  and the driving force/torque from the rotor  32  of the motor  3  can be combined at the rotor support assembly  4 . Furthermore, the rotor support assembly  4  of the modular transmission mechanism is in drive coupling with the input shaft of the transmission via the output assembly  9 . Therefore, the combined driving force/torque can be transmitted to the input shaft of the transmission via the output assembly  9 . 
     More specifically, in the hybrid power system with the P2 architecture shown in  FIG. 2 , a transmission path of the driving force/torque from the engine is as follows: the engine output shaft  7 →the input/output bracket  53  of the clutch  5 →the friction disks  52  of the clutch  5 →the pressure plates  51   a ,  51   b  and  51   c  of the clutch  5 →the rotor flange  42 →the rotor bracket  41 →the flexible plate  91 →the hub core  92  of the flexible plate→the input shaft of the transmission; and a transmission path of the driving force/torque from the motor  3  is as follows: the rotor  32 →the rotor bracket  41 →the flexible plate  91 →the hub core  92  of the flexible plate→the input shaft of the transmission. 
     The hybrid power system with the P2 architecture implemented by using the modular transmission mechanism for a hybrid power system according to the present invention is described above, and a hybrid power system with a P1 architecture implemented by using the modular transmission mechanism for a hybrid power system according to the present invention will be described below. 
     (Hybrid Power System with the P1 Architecture) 
     The hybrid power system with the P1 architecture comprises a modular transmission mechanism for a hybrid power system according to the present invention, an engine (not shown), a transmission (not shown), and the like, wherein the modular transmission mechanism for a hybrid power system according to the present invention shown in  FIG. 3  has substantially the same basic structure as the modular transmission mechanism for a hybrid power system according to the present invention shown in  FIG. 2 . In order to implement the hybrid power system with the P1 architecture, only a connection relationship between some components is changed. 
     Specifically, as shown in  FIG. 3 , the central flange  72  of the engine output shaft  7  is fixedly connected to the rotor flange axial portion  422  of the rotor support assembly  4 , instead of being directly and fixedly connected to the input/output bracket  53  of the clutch  5 ; in addition, the output assembly  9  is fixedly connected to the input/output bracket  53  of the clutch  5 , instead of being directly and fixedly connected to the rotor support assembly  4 . In this way, the driving force/torque from the engine output shaft  7  can be directly transmitted to the rotor support assembly  4  without passing through the clutch  5 , the driving force/torque from the rotor  32  and the driving force/torque from the engine output shaft  7  are combined at the rotor support assembly  4 , and then the combined driving force/torque is transmitted to the output assembly  9  via the engagement of the clutch  5 . 
     More specifically, in the hybrid power system with the P1 architecture shown in  FIG. 3 , the transmission path of the driving force/torque from the engine is as follows: the engine output shaft  7 →the rotor flange  42 →the pressure plates  51   a ,  51   b  and  51   c  of the clutch  5 →the friction disks  52  of the clutch  5 →the input/output bracket  53  of the clutch  5 →the flexible plate  91 →the hub core  92  of the flexible plate→the input shaft of the transmission; and the transmission path of the driving force/torque from the motor  3  is as follows: the rotor  32 →the rotor bracket  41 →the rotor flange  42 →the pressure plates  51   a ,  51   b  and  51   c  of the clutch  5 →the friction disks  52  of the clutch  5 →the input/output bracket  53  of the clutch  5 →the flexible plate  91 →the hub core  92  of the flexible plate→the input shaft of the transmission. 
     It can be learned that, due to the adoption of the modular transmission mechanism for a hybrid power system according to the present invention, the hybrid power system can be converted between the P1 architecture and the P2 architecture with only few changes in the structure. 
     Certainly, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art can make various modifications to the above-mentioned embodiments of the present invention without departing from the scope of the present invention under the teaching of the present invention. 
     (i) In the above-mentioned description, only an operating mode in which the engine and the motor of each hybrid power system are jointly used for driving is described. The charging of a battery through the motor by using the driving force/torque from the engine can be implemented by appropriately controlling the engagement/disengagement of the clutch, which will not be further described herein. 
     (ii) Since the clutch  5  of the modular transmission mechanism for a hybrid power system according to the present invention is arranged on the radial inside of the motor  3 , which makes the motor  3  and the clutch  5  overlap in the axial direction A, this arrangement reduces a lateral dimension of the entire hybrid power system compared with a mode of side-by-side configuration of the clutch  5  and the motor  3  in the prior art. 
     (iii) Although not described above, the modular transmission mechanism for a hybrid power system according to the present invention may be further provided with a revolution speed sensor RE. The revolution speed sensor RE may be arranged on the cylinder body  61  of the concentric slave cylinder  6  and the rotor bracket  41  and configured to sense the revolving speed of the rotor  32 . 
     (iv) Although not described above, the clutch  5  of the modular transmission mechanism for a hybrid power system according to the present invention can adjust various parameters of the clutch based on actual needs (torque capacity and heat capacity of the clutch  5 ). 
     (v) Although not described above, in a specific but non-limiting example, an outer diameter of the stator  31  is 277 mm, an axial dimension of the stator  31  is about 80 mm, and an inner diameter of the rotor  32  is 182 mm. 
     (vi) In the present invention, existing products can be used as the concentric slave cylinder  6  (modular clutch actuator  62 ), the shock absorber  8  and the output assembly  9  to reduce costs. 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
             ICE engine 
             EM 1  first motor 
             EM 2  second motor 
             K 0  clutch 
             DHT transmission 
               1  housing 
               11  housing radial portion 
               12  first housing axial portion 
               13  second housing axial portion 
               2  cooling jacket 
               3  motor 
               31  stator 
               32  rotor 
               4  rotor support assembly 
               41  rotor bracket 
               42  rotor flange 
               421  rotor flange radial portion 
               422  rotor flange axial portion 
               423  axial stopper 
               5  clutch 
               51   a  first pressure plate 
               51   b  second pressure plate 
               51   c  third pressure plate 
               52  friction disks 
               53  input/output bracket 
               6  concentric slave cylinder 
               61  cylinder body 
               62  modular clutch actuator 
               63  release bearing 
               64  piston 
               7  engine output shaft 
               71  shaft portion 
               72  central flange 
               8  shock absorber 
               9  output assembly 
               91  flexible plate 
               92  hub core of a flexible plate 
             RE revolution speed sensor 
             A axial direction 
             R radial direction 
             O central axis