Patent Publication Number: US-10787771-B2

Title: Rail vehicle having stabilizer workhead with powered axles

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional App. Ser. No. 62/371,508, filed on Aug. 5, 2016, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Railroads are generally constructed of a pair of elongated, substantially parallel rails, which are coupled to a plurality of laterally extending ties via metal tie plates and spikes and/or spring clip fasteners. The rails and ties are disposed on a ballast bed formed of hard particulate material, such as gravel. In many instances, including upon initial installation, the ties may not be disposed tightly within the ballast bed. 
     Stabilizers have been used to stabilize railroad ties into the ballast bed, while also testing the integrity of the rails and ties. Conventional stabilizers rely on hydraulic cylinders positioned on a frame to generate downward forces. The weight of the frame carrying such cylinders is generally more than the amount of force applied in the downward direction so that the frame will not lift off of the rail. This arrangement requires heavy, manned machinery, which adds to the inefficiency and cost of the stabilizing operation. Accordingly, lightweight stabilizers that may be deployed for applications requiring mobility and quick setups are needed. 
     BRIEF SUMMARY 
     The present disclosure generally relates to a track stabilizer for use in stabilizing railroad ties into ballast bed. The track stabilizer vehicle according to the present disclosure is lightweight, which allows the stabilizer vehicle to be deployed for applications where mobility and quick setups are required. To accommodate such applications, the stabilizer workhead includes powered axles, such that the axles assist with travel of the stabilizer vehicle along rails. Such an arrangement is particularly useful where the lightweight stabilizer vehicle must travel along challenging grades. The axles may be powered via a hydraulic motor operatively coupled to the wheel assembly. Related methods are described. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference is now made to the following descriptions taken in conjunction with the accompanying drawings. 
         FIG. 1A  illustrates a side view of a manned track stabilizer according to one embodiment of the present disclosure; 
         FIG. 1B  illustrates a side view of a drone track stabilizer according to another embodiment of the present disclosure; 
         FIG. 2A  illustrates a front perspective view of a wheel assembly for a track stabilizer according to the present disclosure; 
         FIG. 2B  illustrates a rear perspective view of the wheel assembly of  FIG. 2A ; 
         FIG. 3  illustrates a top sectional view of the wheel assembly of  FIG. 2A ; 
         FIG. 4  illustrates a perspective view of a track stabilization workhead unit according to the principles of the present disclosure; and 
         FIG. 5  illustrates a top view of the track stabilization unit of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments of a track stabilizer and methods of using a track stabilizer according to the present disclosure are described. It is to be understood, however, that the following explanation is merely exemplary in describing the devices and methods of the present disclosure. Accordingly, several modifications, changes and substitutions are contemplated. 
     A rail vehicle having a track stabilization workhead unit according to the present disclosure is depicted as reference numeral  10  in  FIG. 1A . The rail vehicle  10  includes a frame  12 , which is operatively coupled to a plurality of rail wheels  14 . The rail vehicle  10  further includes an engine  16  for propelling the rail vehicle along a track  18 . An operator cabin  20  is disposed at a rearward end of the rail vehicle  10 . A track stabilization workhead unit  22  is operatively coupled to the frame  12  and depends downwardly therefrom. The track stabilization workhead unit  22  may include a plurality of wheels  24 , which operatively engage the track  18  to allow for movement of the track stabilization workhead unit along the track when in operation. In one embodiment, the track stabilization workhead unit  22  includes eight wheels  24 . 
     The track stabilization workhead unit  22  may be lowered into contact with the track  18  via a pair of hydraulic cylinders  25  disposed between the frame  12  and the workhead unit. In this manner, the track stabilization workhead unit  22  may have two positions—a first, raised position where the workhead unit is not deployed, and a second, lowered position where the workhead unit is engaged with the track  18  and is operable to perform track stabilization operations. The hydraulic cylinders  25  also function to apply downward force on the track stabilization workhead unit  22  as will be described. 
     Referring to  FIG. 1B , an alternative rail vehicle having a track stabilization workhead unit according to the present disclosure is depicted as reference numeral  30 . In this embodiment, the rail vehicle  30  takes the form of a drone vehicle that may be remotely operated. In this manner, the operator cabin of the embodiment of  FIG. 1A  is removed, thus reducing the size and weight of the rail vehicle  30 . The drone rail vehicle  30  may be operated from another rail vehicle or via operators at a remote location, such as a control center. 
     The track stabilization workhead unit  22  includes a plurality of wheel assemblies  32 , one of which is depicted in  FIGS. 2A and 2B . The wheel assembly  32  includes a pair of rail wheels  24  for moving along the track  18  when engaged therewith. The wheel assembly  32  further includes a frame member  36 , which is disposed between the rail wheels  24  and corresponding motors  38  that power assist the rail wheels as will be described. In some embodiments, the motors  38  are hydraulic motors and are only deployed on two wheels  24  on each side of the track stabilization workhead unit  22  as depicted in  FIGS. 4 and 5 . The wheel assembly  32  further includes a rod member  40  that operatively couples the wheel assembly to the track stabilization unit  22 . The rod member  40  has a flange member  42  disposed on the wheel side of the frame member  36  for securing the rod member to the wheel assembly  32 . The rod member  40  extends through the frame member  36  and includes a connecting portion  44  for connecting to the track stabilization unit  22 . 
     Referring  FIGS. 2A, 2B and 3 , the motor  38  is operatively coupled to a drive shaft or axle  46 , which extends from the motor, through a bearing housing  48 , a stub axle  50  and the drive flange  42 , to drive the corresponding rail wheel  24 . In that regard, the motor  38  is disposed adjacent to the bearing housing  48 , which includes bearings  54  for facilitating rotation of the drive shaft  46  when in operation. The stub axle  50  is disposed through the frame member  36  and includes a flange member  56  that abuts the frame member and the bearing housing  48 . At its distal end, the stub axle  50  is coupled to the drive flange  42 . A locking nut  58  is provided to lock the drive shaft  46  in place such that rotation of the drive shaft imparts rotation to the rail wheel  24 . In this manner, the motor  38  provides a power assist to operation of the rail wheel  24  by imparting rotation to the drive shaft  46 . 
     Referring to  FIGS. 4 and 5 , the track stabilization workhead unit  22  includes a base  60  with a pair of bias cylinders  62  disposed at opposite ends of the workhead unit. The bias cylinders  62  are fixedly coupled to the base  60  at one end and are movably coupled to a bias arm  64  at its opposite end. The bias arm  64 , in turn, is hingedly coupled to the base  60  via a locking plate  66 . In one embodiment, the locking plate  66  is a triangular locking plate. The bias cylinders  62  and bias arms  64  cooperate to apply a lateral force on the rail wheels  24  such that the rail wheels rest against the face of the rail. In this regard, the rail wheels  24  include a lip portion  68  that is forced against the face of the rail to bias the track stabilization workhead unit  22  against the rails during stabilization operations. The lateral force applied against the rails stabilizes the track stabilization workhead unit  22  in the lateral direction. 
     The hydraulic cylinders  25  ( FIG. 1 ) extend vertically and couple to the track stabilization workhead unit  22  at corresponding lugs  70 , which are disposed on the frame members  36  of the wheel assemblies  32 . In this manner, actuation of the hydraulic cylinders  25  applies a downward stabilization force into the track stabilization workhead unit  22 , and therefore the rails of the track  18 . 
     While the hydraulic cylinders  25  are configured to apply a downward stabilization force, the track stabilization workhead unit  22  is also configured to apply a lateral stabilization force. Referring again to  FIG. 1  and also to  FIGS. 4 and 5 , the rail vehicle  10  further includes a workhead  80  for imparting lateral forces on the track stabilization workhead unit  22 . The workhead  80  includes a motor and gearbox  82 , which includes gears on each side of the motor. The gears drive and rotate downwardly extending shafts (encased in shaft holders  84 ), which are coupled to the track stabilization workhead unit  22  at flywheels  86  disposed on the workhead unit. In one embodiment, the flywheels  86  are disposed on octagonal plates coupled to the base  60  of the track stabilization workhead unit  22 . The flywheels  86  are weight-imbalanced and are rotated in opposite directions to impart vibrations in the horizontal plane. That is, rotation of the flywheels  86  causes lateral forces to be applied to the track  18  via the force applied by the track stabilization workhead unit  22  to the rail wheels  24  via the lip portions  68 . 
     In operation, the rail vehicle  10  may travel to a portion of track  18  where track stabilization operations are desired. At this time, the track stabilization workhead unit  22  may be lowered into contact with the track  18  via the hydraulic cylinders  25 . The hydraulic cylinders  25  are then further actuated to apply a downward force to the track stabilization workhead unit  22 , thereby stabilizing the track  18  in the vertical direction. At the same time, the track  18  may be stabilized laterally through the application of lateral forces against the track. As such, the motor may be actuated to impart rotation to the gears and therefore the shafts that couple to the flywheels  86 . In this manner, the track  18  is stabilized through the application of vertical and lateral forces against the track via the track workhead stabilization unit  22 . 
     The rail vehicle  10  may travel along the rails during application of the stabilization forces. During this movement, the hydraulic motors  38  power assist the drive shaft  46  of the rail wheel  24 , thus providing a tractive force that assists movement of the rail vehicle  10  along the rails. Prior art track stabilization devices are heavy and difficult to operate in certain conditions, such as over high grade elevations, thus causing the track stabilization unit to drag and operations to slow down. Due to the lightweight nature of the track stabilization workhead unit  22  enabled by the provision of the hydraulic motors  38 , the workhead unit of the present disclosure more easily traverses track having an elevated grade. The powered axles of the present disclosure also reduces the amount of downward force that needs to be applied given that the track stabilization workhead unit  22  is lighter than prior art units. 
     While various embodiments in accordance with the disclosed principles have been described above, it should be understood that they have been presented by way of example only, and are not limiting. For example, while hydraulic motors  38  are described as being coupled to the wheel assembly through a drive shaft arrangement, other coupling arrangements are contemplated, such as chain and sprocket assemblies. Further, while the depicted embodiment shows two hydraulic motors on each side of the track stabilization workhead unit  22 , it is to be appreciated that additional hydraulic motors  38  may be used, or less hydraulic motors may be used, depending on the requirements of the stabilization operations. Thus, the breadth and scope of the invention(s) should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages.