Patent Publication Number: US-10766508-B2

Title: Railcar bogie, wheel load adjusting method thereof, and wheel load adjusting system

Description:
TECHNICAL FIELD 
     The present invention relates to a railcar bogie, a wheel load adjusting method of the railcar bogie, and a wheel load adjusting system. 
     BACKGROUND ART 
     In a railcar bogie, an axle box accommodating a bearing rotatably supporting a wheelset is supported by a bogie frame through an axle box suspension. For example, in PTL 1, a bogie frame includes a pair of side sills extending in a car longitudinal direction and a cross beam connecting the pair of side sills in a car width direction, and an axle box suspension (axle spring) connects an axle box and the side still of the bogie frame. 
     PTL 2 proposes a bogie including: a bogie frame from which side sills are omitted; and plate springs each of which is long in a car longitudinal direction. Longitudinal direction middle portions of the plate springs are supported by respective attaching portions provided at both respective car width direction end portions of the cross beam, and both longitudinal direction ends of each plate spring are inserted into respective spring receiving members formed at the axle boxes. 
     At the time of maintenance of the railcar, wheel load adjusting work is performed, i.e., wheel load balance among wheels is adjusted. For example, in the bogie of PTL 1, a spring constant of the axle spring is changed by inserting a liner between the axle box and the axle spring or pulling out the inserted liner, and with this, the wheel load balance is adjusted. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Laid-Open Patent Application Publication No. 2014-37191 
     PTL 2: Japanese Laid-Open Patent Application Publication No. 55-47950 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the bogie of PTL 1, the wheel load adjusting work needs to be performed by attaching two hydraulic jacks between an axle spring seat and the axle box, and therefore, the working property is low. 
     In the bogie of PTL 2, when adjusting a wheel load, for example, work of forming a gap between the plate spring and the axle box and inserting the liner into the gap may be performed. However, PTL 2 does not specifically mention how to adjust the wheel load. 
     An object of the present invention is to improve a working property of wheel load adjustment in a non-dismantling state of a railcar. 
     Solution to Problem 
     A railcar bogie according to one aspect of the present invention includes: a cross beam supporting a carbody of a railcar; an axle box accommodating a bearing rotatably supporting a wheelset; a supporting member provided at an upper portion of the axle box; a plate spring supporting a car width direction end portion of the cross beam and extending in a car longitudinal direction, the plate spring including a car longitudinal direction end portion supported by the supporting member; and an axle beam coupling the axle box and the cross beam in the car longitudinal direction and opposed to the plate spring in an upward/downward direction, an installation seat being provided at an upper surface of the axle beam, the installation seat including an installation surface on which a pushing-up device is placed, the pushing-up device being configured to push up a lower surface of the plate spring. 
     A wheel load adjusting method of a railcar bogie according to one aspect of the present invention is a wheel load adjusting method of a railcar bogie, the railcar bogie including: a cross beam supporting a carbody of a railcar; an axle box accommodating a bearing rotatably supporting a wheelset; a supporting member provided at an upper portion of the axle box; a plate spring supporting a car width direction end portion of the cross beam and extending in a car longitudinal direction, the plate spring including a car longitudinal direction end portion supported by the supporting member; and an axle beam coupling the axle box and the cross beam in the car longitudinal direction and opposed to the plate spring in an upward/downward direction, the wheel load adjusting method including: placing a pushing-up device on an installation surface of an installation seat provided at an upper surface of the axle beam, the pushing-up device being configured to push up a lower surface of the plate spring; forming a gap between the supporting member and the axle box by pushing up the lower surface of the plate spring by operating the pushing-up device; and inserting a liner into the gap or pulling out the liner inserted between the supporting member and the axle box. 
     A wheel load adjusting system according to one aspect of the present invention includes: a railcar bogie; and a pushing-up device, the railcar bogie including a cross beam supporting a carbody of a railcar; an axle box accommodating a bearing rotatably supporting a wheelset; a supporting member provided at an upper portion of the axle box; a plate spring supporting a car width direction end portion of the cross beam and extending in a car longitudinal direction, the plate spring including a car longitudinal direction end portion supported by the supporting member; and an axle beam coupling the axle box and the cross beam in the car longitudinal direction and opposed to the plate spring in an upward/downward direction, the pushing-up device being configured to push up a lower surface of the plate spring, an installation seat being provided at an upper surface of the axle beam, the installation seat including an installation surface on which the pushing-up device is placed. 
     According to the above configurations, the installation seat on which the pushing-up device can be placed is provided at the upper surface of the axle beam coupling the axle box and the cross beam. With this, when performing work of adjusting wheel load balance in a non-dismantling state, the lower surface of the plate spring can be pushed up by the pushing-up device. Therefore, a gap is formed by pushing up the lower surface of the plate spring, and with this, the liner for adjusting the wheel load balance can be inserted into the gap, or the inserted liner can be easily pulled out from the gap. On this account, in the non-dismantling state of the railcar including the plate spring type railcar bogie, it is unnecessary to detach the plate spring for the wheel load adjustment. Thus, the working property of the wheel load adjustment can be improved. 
     Advantageous Effects of Invention 
     According to the present invention, the working property of the wheel load adjustment in the non-dismantling state of the railcar can be improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view of a railcar bogie according to an embodiment. 
         FIG. 2  is a partially sectional side view showing major components of the bogie of  FIG. 1  with a pushing-up device provided at an axle beam of the bogie. 
         FIG. 3  is a plan view showing an axle box of  FIG. 2  and its periphery. 
         FIG. 4  is a plan view showing first and second liners shown in  FIG. 2 . 
         FIG. 5  is a diagram showing that one first liner and two second liners are inserted into the axle box shown in  FIG. 2 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment will be explained with reference to the drawings. In the drawings, the same reference signs are used for the same or corresponding components, and a repetition of the same explanation is avoided. 
       FIG. 1  is a side view of a railcar bogie  1  according to the embodiment. As shown in  FIG. 1 , the railcar bogie (hereinafter referred to as a “bogie”)  1  includes a bogie frame  3  configured to support a carbody  30  through an air spring  2 . The bogie frame  3  includes a cross beam  4  extending in a car width direction at a car longitudinal direction middle of the bogie  1 . However, unlike the configuration of a conventional bogie frame, the bogie frame  3  does not include side sills extending in a car longitudinal direction from both respective car width direction end portions  4   a  of the cross beam  4 . 
     Axles  6  each extending in the car width direction are arranged at both respective car longitudinal direction sides of the cross beam  4 . Wheels  7  are press-fitted to both respective car width direction sides of each of the axles  6 . The axle  6  and the wheels  7  constitute a wheelset  15 . A pair of wheelsets  15  provided at the bogie  1  are arranged at both respective car longitudinal direction sides of the cross beam  4  so as to be spaced apart from each other. Bearings  8  rotatably supporting the wheels  7  are provided at both respective car width direction end portions of each axle  6  so as to be located outside the wheels  7  in the car width direction. The bearings  8  are accommodated in respective axle boxes  10 . 
     Each of the axle boxes  10  is elastically coupled to the cross beam  4  of the bogie frame  3  through a corresponding axle box suspension  16 . The axle box suspension  16  includes an axle beam  21  coupling the axle box  10  and the cross beam  4  in the car longitudinal direction. The axle beam  21  is formed integrally with the axle box  10  and extends from the axle box  10  toward the cross beam  4  in the car longitudinal direction. A tubular portion  21   b  (see  FIG. 2 ) that is open at both car width direction sides is formed at a tip end of the axle beam  21 . The tubular portion  21   b  is elastically coupled to a receiving seat  4   b  through a rubber bushing and a core rod (not shown), the receiving seat  4   b  being provided at the car width direction end portion  4   a  of the cross beam  4 . 
     Each of plate springs  9  extends between the axle box  10  and the cross beam  4  in the car longitudinal direction. Car longitudinal direction middle portions  9   a  of the plate springs  9  support the respective car width direction end portions  4   a  of the cross beam  4  from below, and both car longitudinal direction end portions  9   b  of each of the plate springs  9  are indirectly supported by the respective axle boxes  10 . To be specific, the plate spring  9  has both the function of a primary suspension and the function of a conventional side sill. 
     Both car longitudinal direction end portions  9   b  of each of the plate springs  9  are supported by the respective axle boxes  10  through respective supporting members  31 . Each of the supporting members  31  is provided at an upper portion of the axle box  10 . The supporting member  31  includes a receiving member  32  and a vibrationproof rubber unit  33 . The receiving member  32  supports the car longitudinal direction end portion  9   b  of the plate spring  9  from below. The vibrationproof rubber unit  33  is substantially columnar and is inserted between the axle box  10  and the receiving member  32 . The vibrationproof rubber unit  33  is constituted by a plurality of rubber plates  33   a  and a plurality of metal plates  33   b  interposed among the plurality of rubber plates  33   a  (see  FIG. 2 ). An upper surface of the vibrationproof rubber unit  33  is inclined obliquely downward toward a middle side in the car longitudinal direction. It should be noted that the upper surface of the vibrationproof rubber unit  33  does not have to be inclined as long as the upper surface of the vibrationproof rubber unit  33  is substantially parallel to a lower surface of the car longitudinal direction end portion  9   b  of the plate spring  9 . 
     The axle box  10  includes: an axle box main body  11  in which the bearing  8  is accommodated; and a spring seat  12  indirectly supporting the plate spring  9 . In the present embodiment, the spring seat  12  is formed integrally with the axle box main body  11 . A liner set  50  constituted by a plurality of liners  51  and  52  (see  FIG. 4 ) described below is interposed between the spring seat  12  and the vibrationproof rubber unit  33 , specifically, between an upper surface of the spring seat  12  and a lower surface of the vibrationproof rubber unit  33 . 
     The liner set  50  is a group of liners used to adjust wheel load balance among the wheels  7  in a non-dismantling state of a railcar. Wheel load adjusting work is performed by selectively interposing the liner set  50  between the plate spring  9  and the axle box  10  through which a load from the carbody  30  is transferred to the wheel  7 . 
       FIG. 2  is a side view showing major components of the bogie  1  with a hydraulic jack  25  provided at an upper surface  21   a  of the axle beam  21  shown in  FIG. 1 .  FIG. 3  is a plan view showing the axle box  10  of  FIG. 2  and its periphery. As shown in  FIGS. 2 and 3 , the axle beam  21  includes an axle beam main body portion  22  and an axle beam end portion  23 . The axle beam main body portion  22  includes: a pair of side plate portions  41  extending from the axle box  10  in the car longitudinal direction; and a coupling plate portion  42  coupling the pair of side plate portions  41  in the car width direction. A sectional shape of the axle beam main body portion  22  when viewed from the car longitudinal direction is an H shape. 
     The axle beam main body portion  22  is provided with an installation seat  43  at which the hydraulic jack  25  can be placed. Specifically, the installation seat  43  is provided at an upper surface  42   a  of the coupling plate portion  42  while being covered with the pair of side plate portions  41  from both sides in the car width direction. The installation seat  43  may be formed integrally with the axle beam  21  or may be fixed to the axle beam  21  by welding or the like. 
     The installation seat  43  includes an installation surface  43   a  at which the hydraulic jack  25  can be placed, and the installation surface  43   a  is substantially parallel to a lower surface  9   c  of the plate spring  9 . An inclination angle of the installation surface  43   a  is different from an inclination angle of the upper surface  42   a  of the coupling plate portion  42 . 
     The hydraulic jack  25  is attached in a direction substantially vertical to the lower surface  9   c  of the plate spring  9 . Since the lower surface  9   c  of the plate spring  9  is inclined with respect to a horizontal surface, the hydraulic jack  25  is provided so as to be also inclined with respect to the horizontal surface. 
     As shown in  FIG. 2 , a wheel load adjusting system  60  is substantially constituted by the bogie  1  and the hydraulic jack  25 . The hydraulic jack  25  includes: a substantially cylindrical cylinder  25   a  including an oil chamber to which operating oil is supplied; and a piston  25   b  which partially projects from an upper surface of the cylinder  25   a . The piston  25   b  expands and contracts in an axial direction. 
     When performing the wheel load adjusting work, a worker places the hydraulic jack  25  on the installation seat  43  provided at the coupling plate portion  42 . The installation seat  43  is covered with the pair of side plate portions  41  of the axle beam  21  from both sides in the car width direction. When the hydraulic jack  25  is placed at the installation seat  43 , the hydraulic jack  25  is arranged so as to be surrounded by the pair of side plate portions  41  and coupling plate portion  42  of the axle beam  21 , the plate spring  9 , and the axle box main body  11 . Therefore, the hydraulic jack  25  is prevented from falling from an installation position when the hydraulic jack  25  is operated. 
     A pad  17  made of steel is attached to the lower surface  9   c  of the plate spring  9 , and a rubber plate is attached to a surface of the pad  17 , the surface contacting the plate spring  9 . The pad  17  includes: a groove portion  17   a  in which an upper end portion of the piston  25   b  is fitted; and a contact surface  17   b . The pad  17  is attached when placing the hydraulic jack  25  in the wheel load adjusting work. As shown in  FIG. 2 , the contact surface  17   b  is subjected to spherical surface processing. With this, even when there is an angular difference between an upper surface of the hydraulic jack  25  and the lower surface  9   c  of the plate spring  9 , such difference can be absorbed, and force from the hydraulic jack  25  can be applied to the lower surface  9   c  of the plate spring  9  in a direction vertical to the lower surface  9   c . When a height of the hydraulic jack  25  is smaller than an interval between the pad  17  and the installation seat  43 , a spacer member having a predetermined thickness may be interposed between a lower surface of the cylinder  25   a  and the installation surface  43   a  of the installation seat  43 . 
     In the present embodiment, the liner set  50  is interposed between the spring seat  12  of the axle box  10  and the vibrationproof rubber unit  33  in advance. It should be noted that the liner set  50  may be interposed between the vibrationproof rubber unit  33  and the receiving member  32 . The illustrated liner set  50  of the present embodiment is constituted by a plurality of liners including one first liner  51  and two second liners  52 , the first and second liners  51  and  52  being different in thickness from each other. It should be noted that to realize appropriate wheel load values, the number of liners and the thicknesses of the liners are suitably selected. The shape of the liner will be described later. 
     The spring seat  12  includes an installation portion  12   a  having a substantially circular shape in a plan view, and the liners  51  and  52  are provided at the installation portion  12   a . An upper surface S of the installation portion  12   a  is substantially parallel to the lower surface  9   c  of the plate spring  9  and is inclined obliquely downward toward the middle side in the car longitudinal direction. 
     A first projecting portion  12   c  and a second projecting portion  12   d  are formed at the spring seat  12 . The first projecting portion  12   c  projects upward from a middle of the installation portion  12   a , and the second projecting portion  12   d  projects upward from a car longitudinal direction end portion of the spring seat  12 . The first projecting portion  12   c  is substantially columnar and is inserted into a lower through hole  33   c  formed on the lower surface of the vibrationproof rubber unit  33 . The second projecting portion  12   d  is located adjacent to a protruding portion  12   b  of the installation portion  12   a  and projects upward from the protruding portion  12   b . Each of the first liner  51  and the second liner  52  engages with the first projecting portion  12   c  and the second projecting portion  12   d.    
     The receiving member  32  has a substantially rectangular shape in a plan view and supports the car longitudinal direction end portion  9   b  of the plate spring  9 . The receiving member  32  includes a bottom wall portion  32   a , an outer wall portion  32   b , and a projecting portion  32   c  projecting downward from a lower surface of the bottom wall portion  32   a . The projecting portion  32   c  is inserted into an upper through hole  33   d  of the vibrationproof rubber unit  33 . 
     Next, the shapes of the liners  51  and  52  and the like will be explained. 
       FIG. 4A  is a plan view of the first liner  51  shown in  FIG. 2 .  FIG. 4B  is a plan view of the second liner  52  shown in  FIG. 2 . As shown in  FIGS. 4A and 4B , the first liner  51  includes a pressure receiving portion  51   a , a first engaging portion  51   b , and a second engaging portion  51   c , and the second liner  52  includes a pressure receiving portion  52   a , a first engaging portion  52   b , and a second engaging portion  52   c . The pressure receiving portions  51   a  and  52   a  receives a load from the plate spring  9 . In a plan view, each of outer edges of the pressure receiving portions  51   a  and  52   a  has a substantially C shape obtained by cutting out a part of a circle. 
     The first engaging portion ( 51   b ,  52   b ) is formed by recessing a part of the outer edge of the pressure receiving portion ( 51   a ,  52   a ) inward. Specifically, the first engaging portion ( 51   b ,  52   b ) is recessed toward a center P of a circle, a part of the circle being formed by the outer edge of the pressure receiving portion ( 51   a ,  52   a ). The second engaging portion ( 51   c ,  52   c ) projects outward from the pressure receiving portion ( 51   a ,  52   a ) at an opposite side of the first engaging portion ( 51   b ,  52   b ) and includes a concave cutout portion ( 51   d ,  52   d ) at a tip end of the second engaging portion ( 51   c ,  52   c ). A cutout width of the cutout portion ( 51   d ,  52   d ) is set to be equal to or slightly larger than a car width direction size of the second projecting portion  12   d.    
     The first liner  51  and the second liner  52  are different in thickness from each other, and a width direction size W 1  of the first liner  51  is smaller than a width direction size W 2  of the second engaging portion  52   c . A worker performs work of attaching and detaching the liner in the car longitudinal direction by holding the second engaging portion of the liner with a tool, such as pliers. Since the width of the second engaging portion is different depending on the thickness of the liner, the liners of different thicknesses are easily distinguished. Thus, the attaching and detaching work is facilitated. 
     As shown in  FIGS. 3 and 4 , when the liners  51  and  52  are inserted between the spring seat  12  and the vibrationproof rubber unit  33 , the first engaging portions  51   b  and  52   b  engage with the first projecting portion  12   c  of the spring seat  12 , and the second engaging portions  51   c  and  52   c  engage with the second projecting portion  12   d  of the spring seat  12 . 
     Since the first engaging portions  51   b  and  52   b  of the liners  51  and  52  engage with the first engaged portion  12   c  located at a center of the spring seat  12 , the liners  51  and  52  are restricted from being displaced inward in the car longitudinal direction and the car width direction. Further, since the second engaging portions  51   c  and  52   c  engage with the second engaged portion  12   d  provided at a car longitudinal direction outer end portion of the spring seat  12 , the liners  51  and  52  are restricted from being displaced outward in the car longitudinal direction. Further, since the concave cutout portions  51   d  and  52   d  fits the second engaged portion  12   d , the liners  51  and  52  are also restricted from being displaced rotationally about the first engaged portion  12   c.    
       FIG. 5  is a diagram showing that one first liner  51  and two second liners  52  are inserted into the axle box  10 . As shown in  FIG. 5 , the thin first liner  51  is inserted under the thick second liner  52  and is sandwiched by the spring seat  12  and the second liner  52 . Since the width direction size W 1  of the cutout portion  51   d  of the first liner  51  is smaller than the width direction size W 2  of the cutout portion  52   d  of the second liner  52  as described above, a level difference portion W 3  is formed between the second engaging portion  51   c  of the first liner  51  and the second engaging portion  52   c  of the second liner  52 . With this, a worker can easily pull out the desired liner by holding the second engaging portion. 
     In the bogie  1  and the wheel load adjusting system configured as above, the wheel load adjustment is performed by the following steps. 
     To be specific, in a first step, a pushing-up device  25  (see  FIG. 2 ), such as a hydraulic jack, is placed at the axle beam  21 . Next, in a second step, the hydraulic jack  25  operates to push up the lower surface  9   c  of the plate spring  9 . With this, a gap is formed between the receiving member  32  and the vibrationproof rubber unit  33 . Last, in a third step, by lifting the vibrationproof rubber unit  33 , a gap is formed between the spring seat  12  of the axle box  10  and the vibrationproof rubber unit  33 . Thus, the liners  51  and  52  can be inserted into the gap, or the inserted liners  51  and  52  can be pulled out from the gap. 
     The bogie  1  and the wheel load adjusting system  60  configured as above have the following effects. 
     In the bogie  1  including the plate spring  9  and in the wheel load adjusting system  60  including the bogie  1 , the installation seat  43  at which the hydraulic jack  25  can be placed is provided at the upper surface  21   a  of the axle beam  21  opposed to the plate spring  9  in an upward/downward direction. With this, in the wheel load adjusting work, the lower surface  9   c  of the plate spring  9  can be pushed up by the hydraulic jack  25 . Therefore, by pushing up the lower surface  9   c  of the plate spring  9  to form a gap between the spring seat  12  and the vibrationproof rubber unit  33 , the liners  51  and  52  for adjusting the wheel load balance can be attached or detached. On this account, when performing the wheel load adjusting work in the non-dismantling state of the railcar including the plate spring type bogie  1 , it is unnecessary to detach the plate spring  9 . Thus, the working property of the wheel load adjustment can be improved. 
     In wheel load adjusting work of a bogie including a typical bogie frame, two hydraulic jacks are required for each axle box. However, according to the present embodiment, the wheel load adjusting work can be performed by one hydraulic jack  25 . Therefore, the working property can be improved. 
     Since the installation surface  43   a  of the installation seat  43  is substantially parallel to the lower surface  9   c  of the plate spring  9 , the hydraulic jack  25  can be easily attached in a direction substantially vertical to the plate spring  9 . Therefore, pressing force generated by the hydraulic jack  25  is easily applied to the lower surface  9   c  of the plate spring  9  in the direction substantially vertical to the lower surface  9   c . Further, the pressing force necessary in the wheel load adjusting work can be made minimum as compared to a case where the hydraulic jack is attached so as to be inclined with respect to the lower surface of the plate spring. 
     The installation seat  43  is provided at the upper surface  42   a  of the coupling plate portion  42  so as to be covered with the pair of side plate portions  41  of the axle beam  21  from both sides in the car longitudinal direction and both sides in the car width direction. With this, when the hydraulic jack  25  is placed on the installation seat  43 , the hydraulic jack  25  is arranged so as to be surrounded by the pair of side plate portions  41 , the coupling plate portion  42 , the plate spring  9 , and the axle box main body  11 , so that the hydraulic jack  25  can be prevented from falling outward from the axle beam  21 . 
     In a side view, the inclination angle of the installation surface  43   a  of the installation seat  43  is different from the inclination angle of the upper surface  42   a  of the coupling plate portion  42 . With this, the installation seat  43  and the coupling plate portion  42  can be designed independently, and this can improve the degree of freedom of the design. 
     The receiving member  32  is fixed to the vibrationproof rubber unit  33 , and a cover member  34  covering the car longitudinal direction end portion  9   b  of the plate spring  9  from above is fixed to the receiving member  32 . With this, when the hydraulic jack  25  pushes up the lower surface  9   c  of the plate spring  9 , the receiving member  32  is also pushed upward together with the plate spring  9 . As a result, a gap can be formed between the vibrationproof rubber unit  33  and the receiving member  32 . After that, by lifting the vibrationproof rubber unit  33 , a gap to or from which the liner is attached or detached can be formed between the spring seat  12  of the axle box  10  and the vibrationproof rubber unit  33 . 
     The first liner  51  and the second liner  52  which are different in thickness from each other include the respective second engaging portions  51   c  and  52   c  which are different in outer shape from each other. In the present embodiment, the second engaging portion  52   c  of the second liner  52  is larger in width direction size than the second engaging portion  51   c  of the first liner  51 . Therefore, when the first liner  51  and the second liner  52  are stacked between the spring seat  12  and the vibrationproof rubber unit  33 , a level difference is formed between the second engaging portion  51   c  of the first liner  51  and the second engaging portion  52   c  of the second liner  52 . On this account, a worker can easily recognize a thickness difference between the stacked liners  51  and  52  based on the level difference and can easily hold the second engaging portion of the desired liner as a holding margin. With this, the working property when performing, for example, work of pulling out the liner having a desired thickness among the plurality of liners  51  and  52  is improved. 
     Since the thin first liner  51  is sandwiched between the thick second liner  52  and the spring seat  12  of the axle box  10 , the second engaging portion  51   c  of the first liner  51  is hardly detached from the second engaged portion  12   d  of the axle box  10 . Thus, the first liner  51  can be prevented from falling off from the axle box  10  while realizing a satisfactory engaging state. Since the outer shape of an upper layer is larger among the outer shapes of the second engaging portions  51   c  and  52   c  stacked on each other, the second engaging portion  52   c  of the upper layer is easily held, and work of pulling out the liners  51  and  52  in order from the upper layer can be easily performed. 
     The present invention is not limited to the above embodiment, and modifications, additions, and eliminations may be made within the scope of the present invention. In the above embodiment, the width direction sizes W 1  and W 2  of the second engaging portions  51   c  and  52   c  of the liners  51  and  52  are made different from each other, and with this, the outer shapes of the second engaging portions  51   c  and  52   c  are made different from each other. However, the above embodiment is not limited to this configuration, and the outer shapes of the second engaging portions  51   c  and  52   c  may be any shapes as long as the thickness difference between the liners  51  and  52  engaged with the second engaged portion  12   d  provided at the spring seat  12  of the axle box  10  is recognizable. For example, colors of the second engaging portions  51   c  and  52   c  may be made different from each other by painting. In the above embodiment, the second engaged portion  12   d  provided at the spring seat  12  of the axle box  10  projects outward from the car longitudinal direction outer end portion of the installation portion  12   a . However, the above embodiment is not limited to this. For example, the second engaged portion  12   d  may project outward from a car width direction outer end portion of the installation portion  12   a . To be specific, the liners  51  and  52  may be inserted between the spring seat  12  and the vibrationproof rubber unit  33  from an outside in the car width direction. The pushing-up device  25  is not limited to the hydraulic jack and may be an air jack or the like. In the above embodiment, there are two types of liners that are different in thickness from each other, but there may be two or more types of liners. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  railcar bogie 
               4  cross beam 
               4  wheelset 
               9  plate spring 
               9   c  lower surface 
               10  axle box 
               21  axle beam 
               21   a  upper surface 
               25  pushing-up device 
               30  carbody 
               31  supporting member 
               32  receiving member 
               34  cover member 
               41  side plate portion 
               42  coupling plate portion 
               43  installation seat 
               43   a  installation surface 
               51  first liner 
               51   a  pressure receiving portion 
               51   c  second engaging portion (engaging portion) 
               52  second liner 
               52   a  pressure receiving portion 
               52   c  second engaging portion (engaging portion) 
               60  wheel load adjusting system