Patent Publication Number: US-2022212696-A1

Title: Bogie framework of rail vehicle and bogie

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Chinese patent application No. 201910462853X, filed on May 30, 2019, entitled “Bogie Framework of Rail Vehicle and Bogie”, which is hereby incorporated by reference in its entirety. 
     FIELD OF TECHNOLOGY 
     The present application relates to the technical field of rail vehicles, and in particular to a bogie framework of rail vehicle and a bogie. 
     BACKGROUND 
     As important parts of rail vehicles, bogie frames directly determine the power performance and safety performance of the rail vehicles. For the bogie frames nowadays, a motor mounting seat and a gearbox boom seat are formed thereon, and a motor and a gearbox are mounted through the motor mounting seat and the gearbox boom seat respectively. One problem of this type of bogie frame is that the motor mounting seat and the gearbox boom seat need to be additionally provided, which results in low efficiency of disassembly and assembly of the bogie. Moreover, after the motor and the gearbox are mounted on the bogie frame, the height of the undercarriage will be excessive, that is, the height of the rail vehicle floor from the ground will be over high, which affects the escape and evacuation of passengers and reduce the safety of operation. In addition, the excessive height of the rail vehicle floor from the ground will also weaken the driving safety and reduce the rolling resistance of the rail vehicle. 
     BRIEF SUMMARY 
     The present application is intended to address at least one of the problems above. 
     An objective of the present application is to provide a bogie framework of rail vehicle to solve the technical problems of low bogie disassembly and assembly efficiency and excessive height of the rail vehicle floor from the ground. 
     In order to achieve this objective, the present application provides a bogie framework of rail vehicle, including a first end beam, a second end beam, and a box beam disposed between the first end beam and the second end beam; the box beam comprises a primary gearbox and a secondary gearbox; the primary gearbox is configured to connect a traction motor and the secondary gearbox, and transmit power from the traction motor to the secondary gearbox; the secondary gearbox is disposed between the primary gearbox and the first end beam, as well as between the primary gearbox and the second end beam. 
     In an embodiment, the box beam further includes a motor box of the traction motor, the motor box is symmetrically disposed on both sides of the primary gearbox, and the motor box, the primary gearbox, and the secondary gearbox are connected to form a cross-shaped beam. 
     In an embodiment, the primary gearbox includes a primary box body, the primary box body includes a top plate, a bottom plate, a first side plate connecting the top plate and the bottom plate, and a first end plate connecting the first side plate, and both the first side plate and the first end plate are provided with first avoidance holes; the motor box includes a top support plate, a bottom support plate, and a second end plate connecting the top support plate and the bottom support plate, and the second end plate is provided with a second avoidance hole; the second end plate is disposed corresponding to the first end plate; the secondary gearbox includes a secondary box body, and the secondary box body includes a second connecting flange corresponding to the first side plate. 
     In an embodiment, the secondary box body and the first end beam, as well as the secondary box body and the second end beam are both connected by plug joints. 
     In an embodiment, both the first side plate and the first end plate extend toward an outer side of the top plate, and a mounting platform for air spring is formed between the top plate, the first side plate and the first end plate. 
     In an embodiment, a mounting table is provided on a side of the top plate proximal to the mounting platform, and the mounting table is configured to connect with the secondary gearbox. 
     In an embodiment, the secondary box body is divided into a left box body and a right box body by a vertical longitudinal section, and the left box body and the right box body are each formed with a first connecting flange along an opening. 
     In an embodiment, the secondary box body is provided with a support seat extending outwards, and the secondary gearbox further includes a first wheel axle and a second wheel axle configured to connect traveling wheels on different sides of a wheelset. Both the first wheel axle and the second wheel axle extend from the support seat to an outer side of the secondary box body, and an end of the first wheel axle and an end of the second wheel axle both located inside the secondary box body are connected by a differential. 
     In an embodiment, the motor box further includes a second side plate connecting the top support plate, the bottom support plate, and the second end plate; and the second side plate is provided with a wire bracket and a through hole of a cooling pipeline. 
     The present application also provides a bogie including the above-mentioned bogie framework. 
     The bogie framework and the bogie of the present application has at least the following advantages: the bogie framework of the present application integrates the gearbox on the bogie framework, thereby improving the efficiency of disassembly and assembly of the bogie. In addition, because the gearbox does not need to be additionally provided on the basis of the bogie framework, the height of the rail vehicle floor from the ground can be reduced, and the rolling resistance of the rail vehicle can be enhanced. Further, the integrated design of the gearbox and the bogie framework and the built-in gear drive are conducive to reducing the height of the bogie, meeting the shield requirements of suburban elevated railways, urban tunnels and A-type subway tunnels, and greatly reducing project costs. 
     Further, for the bogie framework of the present application, because the motor box is integrated on the bogie framework, the efficiency of disassembly and assembly of the bogie is further improved, the height of the rail vehicle floor from the ground is reduced, and the rolling resistance of the rail vehicle is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, drawings needed in the descriptions of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description only show some of the embodiments of the present application, and other drawings can be obtained according to these drawings without any creative effort for those skilled in the art. 
         FIG. 1  is a schematic structural top view of a bogie according to an embodiment of the present application; 
         FIG. 2  is a schematic structural side view of a bogie according to an embodiment of the present application; 
         FIG. 3  is a schematic structural front view of a bogie according to an embodiment of the present application; 
         FIG. 4  is a schematic three-dimensional structural diagram showing a rail vehicle bogie with a gearbox according to an embodiment of the present application; 
         FIG. 5  is a schematic structural side view showing a rail vehicle bogie with a gearbox according to an embodiment of the present application; 
         FIG. 6  is a schematic structural top view showing a rail vehicle bogie with a gearbox according to an embodiment of the present application; and 
         FIG. 7  is a schematic diagram showing the connection relationship between a traction motor body and a gearbox according to an embodiment of the present application. 
     
    
    
     REFERENCE NUMERALS 
       1 . primary gearbox;  2 . secondary gearbox;  3 . top plate;  4 . bottom plate;  5 . first side plate;  6 . first end plate;  7 . first connecting flange;  8 . second connecting flange;  9 . mounting platform;  10 . plug joint;  11 . first input shaft;  12 . mounting table;  01 . first end beam;  02 . second end beam;  03 . traction motor body;  04 . coupling;  05 . motor box;  06 . axle box;  07 . guide wheel;  08 . travelling wheel;  09 . central traction mounting seat;  010 . track beam;  011 . limit mounting plate;  301 . top support plate;  302 . bottom support plate;  303 . second side plate. 
     DETAILED DESCRIPTION 
     In order to provide clearer understanding of the objectives, features and advantages of the present disclosure, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other when there is no conflict. 
     In the description of the present application, it should be noted that unless otherwise specified, the orientations or positional relationships indicated by terms such as “center”, “longitudinal”, “lateral”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside” are based on the orientation or positional relationship shown in the drawings, and are merely for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a particular orientation, is constructed and operated in a particular orientation, and thus should not be construed as limiting the present application. Moreover, the terms “first”, “second”, “third”, and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance. 
     In the description of the present application, it should be noted that unless explicitly specified and defined otherwise, the terms “connected with” and “connected to” shall be understood broadly, for example, it may be either fixedly connected or detachably connected, or may be integrated; it may be mechanically connected, or electrically connected; it may be directly connected, or indirectly connected through an intermediate medium. The specific meanings of the terms above in the present application can be understood by those of ordinary skill in the art in accordance with specific conditions. 
     As shown in  FIGS. 1 to 3 , an embodiment provides a bogie framework of rail vehicle, including a first end beam  01 , a second end beam  02 , and a box beam disposed between the first end beam  01  and the second end beam  02 ; the box beam includes a primary gearbox  1  and a secondary gearbox  2 , and the primary gearbox  1  is configured to connect a traction motor and the secondary gearbox  2 , and transmit power from the traction motor to the secondary gearbox  2 ; the secondary gearbox  2  is disposed between the primary gearbox  1  and the first end beam  01 , as well as between the primary gearbox  1  and the second end beam  02 . 
     For this kind of bogie framework, as the gearbox is integrated on the bogie framework, the efficiency of disassembly and assembly of the bogie is improved. In addition, because the gearbox does not need to be additionally provided on the basis of the bogie framework, the height of the rail vehicle floor from the ground can be reduced, and the rolling resistance of the rail vehicle can be enhanced. Further, the integrated design of the gearbox and the bogie framework and the built-in gear drive are conducive to reducing the height of the bogie, meeting the shield requirements of suburban elevated railways, urban tunnels and A-type subway tunnels, and greatly reducing project costs. 
     In addition, the use of this type of bogie framework may reduce the overall weight of the bogie, thereby reducing the wear of tires of the travelling wheel  08  and saving operating costs. 
     It is worth mentioning that the embodiment illustrates the bogie framework of rail vehicle mentioned above only in the case of a monorail vehicle. Without loss of generality, the bogie framework of rail vehicle mentioned above can be applied to dual rail vehicles in addition to monorail vehicles. 
     Taking the double-axle straddling monorail vehicle which may have good running stability, smoothness, comfortable ride, and large passenger capacity as an example, due to its floor structure, the section of a track beam  010  is as high as 1.5 meters, customers therefore wish to optimize the structure of the double-axle straddling monorail transportation system, so as to reduce the floor height of straddling monorail vehicles, facilitate passengers to escape and evacuate, and improve operational safety. 
     When the double-axle straddle monorail vehicle adopts the above-mentioned bogie framework of rail vehicle, the cross section height of the track beam  010  will be greatly reduced. Specifically, the cross section height of the track beam  010  may be reduced by about 600 mm, and thus the level of passenger escape and evacuation is increased without changing the floor height of the vehicle. In addition, combined with the optimization of the vehicle body structure, the total height of passing section of the vehicle and track can be reduced up to about 700 mm, which in turn reduces the cross section height of the tunnels and saves the project cost. 
     In an embodiment, the box beam further includes a motor box  05  of the traction motor, the motor box  05  is symmetrically or nearly symmetrically disposed on both sides of the primary gearbox  1 , and the motor box  05 , the primary gearbox  1 , and the secondary gearbox  2  are connected to form a cross-shaped beam; and the “cross-shaped” beam is just a visual analogy, and it is not strictly required that the motor box  05  and the primary gearbox  1  must be collinear, or the primary gearbox  1  and the secondary gearbox  2  must be perpendicular. 
     Furthermore, the cross-shaped beam and the first end beam  01  and the second end beam  02  may form a double-H-shaped bogie framework. In this case, the primary gearbox  1  and the motor box arranged on both sides of the primary gearbox  1  are connected to form a box beam. 
     For this kind of bogie framework, because the motor box is integrated on the bogie framework, the efficiency of disassembly and assembly of the bogie is further improved, the height of the rail vehicle floor from the ground is reduced, and the rolling resistance of the rail vehicle is improved. 
     The motor box  05  is configured to mount the traction motor body which serves as a power drive unit. Along the power transmission direction of the bogie, the traction motor body is sequentially connected to the primary gearbox  1 , the secondary gearbox  2 , and the wheel axle. Specifically, an output shaft of the traction motor body is connected to a first input shaft  11  of the primary gearbox  1 , an output shaft of the primary gearbox  1  is connected to a second input shaft of the secondary gearbox  2 , and an output shaft of the secondary gearbox  2  is connected to the wheel axle. Furthermore, a transmission unit and a power unit are both integrated on the bogie framework to simplify the structure of the bogie and reduce the weight of the bogie. 
     In combination with the structure of the bogie framework, it can be seen that the transmission direction has changed between the primary gearbox  1  and the secondary gearbox  2 . The power transmission direction in the primary gearbox  1  is along the transverse direction, and the power transmission direction of the secondary gearbox  2  is along the longitudinal direction. 
     For the double-H-shaped bogie framework, it has a good load-bearing capacity, and the gearbox and the motor box  05  do not need to occupy additional space under the vehicle. 
     A central traction mounting seat  09  is fixed on the primary gearbox  1  to facilitate the mounting of a traditional Z-shaped traction device or a traction device of other structural forms. The central traction mounting seat  09  and the primary gearbox  1  are two independent structures, which can in turn facilitate the processing and forming of the central traction mounting seat  09  and the primary gearbox  1  respectively. Moreover, once the structure of the central traction mounting seat  09  is fatigued and damaged, the central traction mounting seat  09  can also be easily repaired or replaced. 
     According to one of the embodiments of the present application, the central traction mounting seat  09  is provided with a transverse stop seat and a vertical stop seat, and in this case, the integrated design of various stops and the central traction mounting seat  09  is provided, which can in turn facilitate the structural maintenance of the bogie framework. 
     According to one of the embodiments of the present application, the distance between the box beam and the first end beam  01  is equal to the distance between the box beam and the second end beam  02 , thereby ensuring the structural symmetry of the double-H-shaped bogie framework. 
     According to one of the embodiments of the present application, both the first end beam  01  and the second end beam  02  are U-shaped beams with an opening facing downward, as shown in  FIG. 2 . Specifically, the U-shaped beam includes cantilever beams and a connecting beam located between the cantilever beams on both sides. The structure of the first end beam  01  and the second end beam  02  may facilitate the installation of the guide wheel  07 . 
     As it should be, the bogie framework of rail vehicle may also include an axle box  06  in addition to the components mentioned above. The axle box  06  is fixed on the gearbox and is arranged longitudinally between the motor box  05  and the first end beam  01 , as well as between the motor box  05  and the second end beam  02 . 
     A mounting groove is formed on the top of the gearbox, and the axle box  06  is fixed in the mounting groove. Compared with the traditional axle box located at the bottom of the bogie framework, not only can the space at the bottom of the bogie framework be saved, but the axle box  06  can also be used as a component of the bogie framework to strengthen the structural strength of the bogie framework. 
     Referring to  FIG. 1 , the axle box  06  is symmetrically arranged on both sides of the box beam to facilitate the symmetrical installation of the wheels. 
     According to one of the embodiments of the present application, each pair of travelling wheels  08  includes a first travelling wheel and a second travelling wheel. The first travelling wheel is connected to the first wheel axle, and the second travelling wheel is connected to the second wheel axle. The gearbox is connected between the first and second wheel axles through a differential. 
     By providing a differential, the speeds of the first travelling wheel and the second travelling wheel of each wheelset may be different, thereby improving the driving safety in the turning process or under other conditions. 
     Referring to  FIGS. 4 and 5 , along the longitudinal direction of the rail vehicle, the secondary gearbox  2  is gradually inclined upward toward the direction away from the primary gearbox  1 . That is, in  FIGS. 4 and 5 , a frame bearing beam formed by the gearbox is recessed downward at the position of the primary gearbox  1 . Because the primary gearbox  1  carries an air spring above it, the vehicle body of the rail vehicle is carried above the air spring, and the travelling wheel has a constant wheel diameter. By making a recess at the primary gearbox  1 , the overall height of the rail vehicle can be reduced, thereby improving the running stability of the rail vehicle and ensuring safety during escape. That is, when other components of the rail vehicle are of inconvenient specifications, the overall height of the rail vehicle can be reduced by designing the gearbox of the rail vehicle into a form that the primary gearbox  1  is relatively concave. 
     The secondary gearbox  2  includes a first secondary gearbox and a second secondary gearbox arranged on both sides of the primary gearbox  1 . The first secondary gearbox is configured to transmit power from the primary gearbox  1  to the front wheelset of the rail vehicle, and the second secondary gearbox is configured to transmit power from the primary gearbox  1  to the rear wheelset of the rail vehicle. 
     When the first secondary gearbox and the second secondary gearbox have the same structure, it is possible but not necessary to symmetrically arrange the first secondary gearbox and the second secondary gearbox on both sides of the primary gearbox  1 . 
     According to one of the embodiments of the present application, the primary gearbox  1  includes a primary box body, the primary box body includes a top plate  3 , a bottom plate  4 , a first side plate  5  connecting the top plate  3  and the bottom plate  4 , and a first end plate  6  connecting the first side plate  5 . By providing the top plate  3 , the bearing surface of the primary gearbox  1  can be increased, so that when the primary gearbox  1  is used as a component of the frame bearing beam, the force is more uniform, and the stress concentration on the primary box body can be prevented. The specific structural forms of the top plate  3 , the bottom plate  4 , the first side plate  5  and the first end plate  6  are not limited, which may be a flat plate structure, a curved plate with a curvature, or a bent plate. Moreover, the primary gearbox  1  has a structure that is not limited by the embodiments here, as long as it can meet the load-bearing requirements. 
     In order to ensure the power transmission from the traction motor body to the wheelset, both the first side plate  5  and the first end plate  6  of the primary gearbox  1  are provided with first avoidance holes. The first avoidance hole on the first end plate  6  is for enabling the connection between the traction motor body and the gear train inside the primary gearbox  1 . Specifically, a first input shaft  11  is provided at the first end plate  6 , and the first input shaft  11  is connected to the coupling  04  of the traction motor body. The first avoidance hole on the first side plate  5  is for enabling the connection between the gear train inside the primary gearbox  1  and the gear train inside the secondary gearbox  2 . 
     In  FIG. 4 , the first side plate  5  of the primary box body refers to the plate structure connected with the secondary gearbox  2 , and the first end plate  6  refers to the trapezoidal plate in  FIG. 4 . 
     It is worth mentioning that in  FIGS. 4 and 5 , the first end plate  6  is designed in the form of a trapezoidal plate, which can make the structure of the primary box body more stable, so that the force received by the top plate  3  is transmitted to the bottom plate  4  through the first side plate  5  and the first end plate  6 , thereby preventing the top plate  3  from being damaged. In addition, designing the first end plate  6  in the form of a trapezoidal plate can also facilitate the installation of the secondary gearbox  2 , so that the secondary gearbox  2  is fixed on the first side plate  5  while the requirement of “along the longitudinal direction of the rail vehicle, the secondary gearbox  2  is gradually inclined upward toward the direction away from the primary gearbox  1 ” is satisfied. 
     Further referring to  FIG. 4 , both the first side plate  5  and the first end plate  6  extend toward an outer side of the top plate  3 , and a mounting platform  9  for air spring is formed between the top plate  3 , the first side plate  5  and the first end plate  6 . The mounting platform  9  is a concave platform formed on the top of the primary gearbox  1 , which makes the installation of the air spring reliable and stable. 
     Referring to  FIGS. 4 and 6 , a mounting table  12  is provided on a side of the top plate  3  proximal to the mounting platform  9 , and the mounting table  12  is configured to connect with the secondary gearbox  2 . For example, the threaded part passes through the secondary gearbox  2  and then penetrates into the mounting table  12  to provide the fixation between the secondary gearbox  2  and the primary gearbox  1 . If the mounting table  12  is not provided, the area on the primary gearbox  1  for connecting the secondary gearbox  2  may be a weak link under force of the primary gearbox  1 . 
     Further, referring to  FIGS. 4 and 6 , the mounting tables  12  corresponding to two first side plates  5  are staggered with each other, so as to meet the distribution requirements of other components. 
     According to one of the embodiments of the present application, the secondary gearbox  2  includes a secondary box body, which is divided into a left box body and a right box body by a vertical longitudinal section. Separating the secondary box body into the left box body and the right box body from the vertical longitudinal section may facilitate the installation of the internal gear train of the secondary box body. Further, in order to facilitate the installation of the gear train of the secondary gearbox  2 , in addition to dividing the secondary box body into multiple parts at the vertical longitudinal section, the secondary box body may also be divided from any other position. 
     Further, the left box body and the right box body are each formed with a first connecting flange  7  along an opening, thereby facilitating the assembly of the left box body and the right box body. The left box body and the right box body may be tightened by circumferential bolts to meet the needs of quick installation. 
     According to one of the embodiments of the present application, a second connecting flange  8  is provided on the end surface of the secondary box body proximal to the primary gearbox  1 . When the primary box body is connected to the secondary box body, the second connecting flange  8  is attached to the first side plate  5  of the primary box body and fixed with a threaded part, so that the second connecting flange  8  bears the shearing force generated by the vibration between the primary box body and the secondary box body. Further, the second connecting flange  8  increases the force-bearing area between the primary box body and the secondary box body, and at the same time may facilitate the connection between the primary box body and the secondary box body. 
     Further, a positioning stop may be provided between the primary box body and the secondary box body to enable quick installation between the primary box body and the secondary box body. 
     In addition, multiple bolt holes may be reserved on the surfaces of the primary box body and the secondary box body to respectively assemble multiple functional components such as traction device (e.g. the central traction mounting seat  09 ), traveling system, frame mounting seat, traction motor body mounting seat, and brake seat. In addition, two independent transmission systems may be arranged in the primary box body and the secondary box body, and the two transmission systems do not interfere with each other, thereby meeting the requirements of independent transmission for the front wheelset and the rear wheelset. 
     According to one of the embodiments of the present application, the secondary gearbox  2  protrudes to form a support seat for connecting with the bearing of the wheelset. The support seat may be used to install the bearing and allow the wheel axle to connect the wheelset after passing through the support seat. 
     Referring again to  FIG. 4 , an end of the secondary gearbox  2  away from the primary gearbox  1  is formed with a plug joint  10  for connecting with the end beam of the framework. By providing the plug joint  10 , the assembly of the bogie framework may be facilitated, and the positioning and connection between the end beam and the gearbox-type frame bearing beam may be enabled. 
     In order to reduce the weight of the bogie framework, a weight reduction hole is formed at the position of the plug joint  10 . 
     According to one of the embodiments of the present application, the primary box body is processed and welded with steel plate, and has a box-shaped structure. The secondary box body is cast and has a sub-box structure. The sub-box surface is a flange surface of the first connecting flange  7 . 
     The aforementioned gearbox of rail vehicle is classified into a primary gearbox  1  and a secondary gearbox  2 , and the primary gearbox  1  and the secondary gearbox  2  are used as the central structure of the bogie to provide installation positions for other functional components of the bogie. 
     In an embodiment, provided is a bogie of rail vehicle, including the above-mentioned bogie framework of rail vehicle, and further including: a traction motor body  03  in the motor box  05 . The traction motor body  03  includes an output shaft; the motor box  05  includes a top support plate  301 , a bottom support plate  302 , and a second end plate connecting the top support plate  301  and the bottom support plate  302 ; a second avoidance hole of the output shaft is formed on the second end plate. 
     The motor box  05  and the traction motor body  03  form the traction motor body of the rail vehicle bogie. 
     As for the traction motor body of rail vehicle bogie, the motor box  05  is provided outside the traction motor body  03 . The top support plate  301  of the motor box  05  may be used to install air springs, the bottom support plate  302  may be used to support the traction motor body  03 , and the second end plate meets the connection requirements of the bogie framework, and thus the motor box  05  may be integrated on the bogie framework of rail vehicle, which simplifies the overall structure of the bogie and is conducive to subsequent maintenance and repair. In addition, the bogie provided with the traction motor body of rail vehicle bogie does not need to be separately and additionally provided with a traction motor body mounting seat, thus the preparation is simple, the structural strength is high, and there is no safety hazard during operation, which solves a series of problems caused by the low integration of the rail vehicle bogie. 
     Further, by integrating the traction motor body and the bogie framework of rail vehicle, it is beneficial to reduce the height of the bogie, meet the shield requirements of suburban elevated railways, urban tunnel and A-type subway tunnel, and greatly reduce project costs. For the rail vehicle equipped with the traction motor body of the rail vehicle bogie, the height of the vehicle floor from the evacuation channel can be reduced, and the escape safety can be improved. 
     It is worth mentioning that the traction motor body  03  may be protected, since the motor box  05  is provided outside the traction motor body  03 , to prevent the traction motor body  03  from being affected by the external environment and prematurely scrapped. 
     It is worth mentioning that the second end plate may be provided at both ends of the traction motor body  03  or only at one end of the traction motor body  03 . For the traction motor body  03 , the two ends are defined along the axial direction of the output shaft thereof. Taking  FIG. 1  as an example, the output shaft of the traction motor body  03  (not shown in  FIG. 1 ) has an axial direction as the longitudinal direction of  FIG. 1 , and then the two ends of the traction motor body  03  are the upper and lower ends in  FIG. 1 . When only one end of the traction motor body  03  is provided with the second end plate, namely the motor box  05  has an open design, the opening position may facilitate the disassembly and assembly of the traction motor body  03 . 
     Further, the motor box  05  further includes a second side plate  303  connecting the top support plate  301 , the bottom support plate  302  and the second end plate. Therefore, the top support plate  301 , the bottom support plate  302 , the second end plate and the second side plate  303  may protect the traction motor body  03  from multiple sides. 
     A wire bracket is provided on the second side plate  303 . Therefore, various sensors of the traction motor body of the rail vehicle bogie may be wired through the wire bracket. By arranging the wire bracket on the second side plate  303 , interference between the wires and other structures of the bogie can be prevented. 
     In the same way, a through hole of a cooling pipeline is formed on the second side plate  303  to facilitate the installation of the cooling pipeline. The cooling pipeline may be a cooling water pipe or a cooling air pipe. When the cooling water pipe is used as the cooling pipeline, the cooling water pipe may be connected to a water tank at the bottom of the vehicle body. Alternatively, it is also possible to additionally provide a cooling water tank connected to the above-mentioned cooling water pipe. By providing a through hole on the second side plate  303  and installing a cooling pipeline based on the through hole, the heat dissipation of the traction motor body  03  can be enhanced, and heat can be prevented from accumulating in the motor box  05 . 
     Referring to  FIG. 7 , the traction motor body  03  also includes a limit mounting plate  011 . The limit mounting plate  011  may be installed between the top support plate  301  and the bottom support plate  302 , to prevent the traction motor body  03  from shaking in the motor box  05 , and ensure the reliability of the installation of the traction motor body  03 . 
     In  FIG. 7 , the limit mounting plate  011  is octagonal or approximately octagonal, and correspondingly, the motor box  05  is a rectangular box. In this case, the limit mounting plate  011  may be in contact with the top support plate  301 , the bottom support plate  302 , and the second side plate  303  of the motor box  05  at the same time, or maintain a slight gap with the top support plate  301 , the bottom support plate  302  and the second side plate  303 , thereby limiting the movement of the traction motor body  03  in each direction. Moreover, since the octagonal limit mounting plate  011  can be regarded as a rectangular plate with four chamfers, the limit mounting plate  011  can easily enter the motor box  05  without scratching the inner wall of the motor box  05 . 
     Further, a screw hole is formed on the limit mounting plate  011 , so that a threaded connection piece passes through the motor box  05  and then enters the screw hole of the limit mounting plate  011  to fix the traction motor body  03  in the motor box  05 . The threaded connection piece mentioned here may be either a bolt or a screw. 
     The implementations above are only used to illustrate the present application, but not to limit the present application. Although the present application has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the present application do not depart from the scope of the technical solutions of the present application, and should all be covered within the scope of the claims of the present application.