Patent Publication Number: US-2023150034-A1

Title: All-electric fixed underfloor wheel sets lathe

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of PCT application No. PCT/CN2022/126742, filed on Oct. 21, 2022, which claims the priority benefit of China application No. 202111236770.2, filed on Oct. 23, 2021. The entireties of PCT application No. PCT/CN2022/126742 and China application No. 202111236770.2 are incorporated herein by reference and made a part of this specification. 
    
    
     TECHNICAL FIELD 
     The present application relates to the technical field of wheel repair apparatus, more particularly to an all-electric fixed underfloor wheel sets lathe. 
     BACKGROUND ART 
     An underfloor wheel sets lathe is an apparatus mainly used for repairing rims and treads of various rail vehicle wheels. 
     In the related art, for example, Chinese invention patent publication No. CN 107344244A discloses a friction pulley floating drive device of a numerically controlled underfloor wheel sets lathe comprising a base, a drive mechanism and a hydraulic mechanism, wherein the drive mechanism is provided on the base, and the hydraulic mechanism is connected to the drive mechanism via a pipeline. The drive mechanism comprises a friction pulley box body, an electric motor, a coupling, an electric motor main shaft, friction driving pulleys, and a hydraulic oil cylinder, wherein the hydraulic oil cylinder and the friction pulley box body are both provided on the base, the hydraulic oil cylinder is connected to the friction pulley box body via a piston rod, the electric motor is provided on the friction pulley box body, the electric motor is connected to the electric motor main shaft via the coupling, the electric motor main shaft is provided in the friction pulley box body, and the friction driving pulleys are provided at the end of the electric motor main shaft. 
     When using the above-mentioned floating drive device for friction pulleys of a numerically controlled underfloor wheel sets lathe, the floating drive device for the friction pulley of the numerically controlled underfloor wheel sets lathe is mounted on a frame of the numerically controlled underfloor wheel sets lathe, wheels are placed on the frame and located directly above friction driving pulleys, a hydraulic oil cylinder is started, the hydraulic oil cylinder drives a friction pulley box body which then drives the friction driving pulleys to rotate, and the friction driving pulleys gradually abut against the bottom of the wheels and lifts the wheel, so that the wheels are separated from a rail. The motor is started to drive the friction driving pulleys to rotate, and the friction driving pulleys drive the wheels to rotate. 
     With regard to the above-mentioned related art, the inventor believes that after the friction driving pulleys lift the wheel, a central axis of the friction driving pulleys are provided at an angle to a central axis of the wheel, and then the contact area between the friction driving pulleys and the wheels is reduced, so that the wear of the friction driving pulleys on the wheels are greater, and there is a defect that the friction driving pulleys become a burden for the repair of the wheel. 
     SUMMARY 
     In order to alleviate the problem of the burden of repairing the wheels caused by the friction driving pulleys, the present application provides an all-electric fixed underfloor wheel sets lathe. 
     The present application provides an all-electric fixed underfloor wheel sets lathe using the following technical solution: an all-electric fixed underfloor wheel sets lathe comprising a frame, two rails provided on the frame, two lathe tools provided on the frame and two sets of wheel driving devices provided on the frame, wherein each set of the wheel driving devices comprises leveling brackets, drive assemblies provided on the leveling brackets, lifting assemblies provided on the leveling brackets and leveling assemblies provided on the leveling brackets, the lifting assemblies and the leveling assemblies are fixedly connected to the frame, the drive assemblies are configured for driving wheels to rotate and the lifting assemblies are configured for lifting the leveling brackets. 
     By using the above-mentioned technical solution, when repairing a wheel, the wheel is driven onto a rail, and then a lifting assembly is operated to lift a leveling bracket which drives the drive assembly to move; the drive assembly moves in a direction close to the wheel; the drive assembly gradually abuts the bottom of the wheel and lifts the wheel, and then the wheel is gradually separated from the rail; after the wheel is separated from the rail, the leveling assembly is operated to drive the leveling bracket which is gradually in a horizontal state, then the drive structure is operated to enable the drive structure to drive the wheel to rotate, then the lathe tool is operated to repair the wheel. 
     A rotation axis of the drive assembly and a rotation axis of the wheel are in a parallel state by adjusting the leveling bracket to a horizontal state, thereby reducing the occurrence of an included angle between the rotation axis of the drive assembly and the rotation axis of the wheel that will affect the contact area between the drive assembly and the wheel, reducing the occurrence of wear on the wheel by the drive assembly, and further reducing the occurrence of a burden on the wheel repair by the drive assembly; at the same time, the leveling assembly can be configured for adjusting the height of the outer side of the leveling bracket, i.e., adjusting the height of one end of the leveling bracket away from the wheel, so that the height of the outer side of the leveling bracket of the two sets of wheel driving devices respectively located at two sides of the rail is consistent, reducing the occurrence of the symmetry decrease of the wheel treads at the two sides after repair, thereby improving the accuracy of wheel tread repair. 
     Alternatively, the lifting assembly comprises a lifting frame and a drive structure for driving the lifting frame, the drive structure is fixedly connected to the frame, and the lifting frame is hinged to the leveling bracket. 
     By using the above-mentioned technical solution, when the wheels are lifted and separated from the rail, the drive structure is operated to lift the lifting frame, the lifting frame drives the leveling bracket to move the drive assembly, and the drive assembly drives the wheels to rise, and then the wheels are separated from the rail, i.e., to lift the wheel. 
     Alternatively, the drive structure comprises a fixed housing, a drive rod having one end slidably connected in a fixed housing, a first ball screw rotatable in the fixed housing and a servo motor fixedly connected to the fixed housing, wherein the servo motor is in transmission connection with a screw of the first ball screw, a nut of the first ball screw is fixedly connected to the drive rod, the drive rod is fixedly connected to the lifting frame, and the fixed housing is fixedly connected to the frame. 
     By using the above-mentioned technical solution, when driving the lifting frame, a servo motor is started, the servo motor drives the screw of the first ball screw to rotate, a nut of the first ball screw rotates relative to the screw and moves along the length direction of the screw, the nut drives the drive rod to move, the drive rod slides relative to the fixed housing, and the drive rod drives the lifting frame while moving, i.e., the lifting frame is driven. 
     Alternatively, the all-electric fixed underfloor wheel sets lathe further comprises a pressure sensor by which the drive rod is fixedly connected to the lifting frame. 
     By using the above-mentioned technical solution, when the drive rod drives the lifting frame, the lifting frame drives the leveling bracket to move the drive assembly, and the drive assembly gradually abuts against the bottom of the wheel, so that the pressure received by the pressure sensor gradually increases, and when the pressure received by the pressure sensor does not change any more, the driving of the lifting frame is discontinued, thereby achieving the effect of facilitating the staff to control the lifting height of the lifting frame. 
     Alternatively, the leveling assembly comprises a leveling housing, a leveling rod having one end slidably connected in the leveling housing, a second ball screw rotatably connected in the leveling housing and a hand-held rod fixedly connected to the second ball screw, wherein a nut of the second ball screw is fixedly connected to the leveling rod which is hinged to the leveling bracket, and the leveling housing is fixedly connected to the frame. 
     By using the above-mentioned technical solution, after the wheels are lifted by adjusting the lifting assembly, a hand-held rod is rotated to rotate the screw rod of the second ball screw; the nut of the second ball screw rotates relative to the screw rod, the nut moves along a length direction of the screw rod and drives the leveling rod to move; the leveling rod and the leveling bracket rotate relative to each other, and then the leveling bracket is gradually in a horizontal state, thereby ensuring the contact area between the drive assembly and the wheels as far as possible, reducing the wear on the wheels by the drive assembly, and further reducing the burden on the wheel repair caused by the drive assembly. 
     Alternatively, the apparatus further comprises a wheel axial limiting device provided in two sets which respectively abut against the inner sides of two wheels, and the wheel axial limiting devices are both configured for limiting the wheels in an axial direction of the wheels. 
     By using the above-mentioned technical solution, when the drive assembly drives the wheels, the wheel axial limiting devices limit the axial movement of the wheels, thereby reducing the occurrence of the wheels moving along their own axial direction during the rotation process, on the one hand, increasing the stability of the wheels when the all-electric fixed underfloor wheel sets lathe repairs the wheels, and on the other hand, improving the efficiency of the all-electric fixed underfloor wheel sets lathe in repairing the wheels. 
     Alternatively, each set of the wheel axial limiting devices comprises device bodies, limiting rods having one end slidably connected in the device bodies, limiting pulleys rotatably connected to the limiting rods, and pushing assemblies for pushing the limiting rods to slide, wherein the limiting pulleys are provided with limiting grooves abutting against the rims of the wheels, and the device bodies are fixedly connected to the frame. 
     By using the above-mentioned technical solution, after the wheels are separated from the rail, the pushing assembly is operated to push the limiting rod which drives the limiting pulley to move, and then the limiting pulley moves towards the direction close to the wheel, so that the limiting groove on the limiting pulley abuts against the rim of the wheel, and when the wheels rotate, the limiting pulley and the wheel rotate relative to each other, thereby achieving the effect of axially limiting the wheel. 
     Alternatively, the pushing assembly comprises a third ball screw and a first drive motor, wherein the first drive motor is in transmission connection with a screw of the third ball screw, a nut of the third ball screw is fixedly connected to the limiting rod, and the first drive motor is fixedly connected to the device body. 
     By using the above-mentioned technical solution, when the limiting rod is driven, the first drive motor is started to drive the first drive motor drives the screw of the third ball screw to rotate, the nut of the first ball screw and the screw rotate relative to each other, the nut moves along the length direction of the screw, and the nut drives the limiting rod to move, i.e., the limiting rod is driven. 
     Alternatively, an outer sleeve of the limiting rod is provided with a guide sleeve having one end slidably connected to the device body, and the guide sleeve moves with the movement of the limiting rod. 
     By using the above-mentioned technical solution, when the limiting rod moves, the limiting rod drives the guide sleeve to move, and the guide sleeve slides relative to the device body; and by providing the guide sleeve on the outside of the limiting rod, the maximum lateral pressure that the limiting rod can bear can be increased, and the occurrence of bending deformation of the limiting rod can be reduced, thereby increasing the stability of the limiting pulley. 
     Alternatively, the device body is provided with a limiting block for limiting the movement of the guide sleeve, a rotation seat is hinged on the limiting rod, the limiting pulley is rotatably connected to the rotation seat having one end near the limiting pulley hinged to the guide sleeve. 
     By using the above-mentioned technical solution, when the limiting rod moves, the guide sleeve moves with the movement of the limiting rod; when the guide sleeve moves to the limit position, the limiting block limits the movement of the guide sleeve; the guide sleeve cannot continue to move; the limiting rod continues to move; the limiting rod drives the rotation seat, and the rotation seat and the guide sleeve rotate relative to each other, so that the central axis of the limiting pulley gradually forms an included angle with the central axis of the wheel, thereby increasing the axial pressure exerted by the limiting pulley on the wheel, thereby increasing the axial limiting effect of the limiting pulley on the wheel. 
     In summary, the present application comprises at least one of the following beneficial technical effects: by providing a leveling bracket, a drive assembly, a lifting assembly and a leveling assembly, after placing wheels on a rail, the lifting assembly lifts the leveling bracket, the leveling bracket drives the drive assembly to move, the drive assembly gradually abuts against the bottom of the wheels and lifts the wheels, and after the wheels are separated from the rail, the leveling assembly is operated to adjust the leveling bracket, so that the leveling bracket is in a horizontal state, thereby reducing the formation of an included angle between the central axis of the drive assembly and the central axis of the wheel, resulting in serious wear on the wheel, and further reducing the burden caused by wheel repair; the leveling assembly can be configured for adjusting the height of the outer side of the leveling bracket, i.e., adjusting the height of one end of the leveling bracket away from the wheel, so that the heights of the outer sides of the leveling brackets of the two sets of wheel driving devices respectively located at two sides of the rail are consistent, reducing the occurrence of the symmetry decrease of the wheel treads at the two sides after repair, and further improving the accuracy of wheel tread repair; by providing a lifting frame and a drive structure, the drive structure is configured for driving the lifting frame, and when the leveling bracket is lifted, the drive structure is started, the drive structure drives the lifting frame, and the lifting frame drives the leveling bracket, i.e., the leveling bracket is lifted; by providing a fixed housing, a drive rod, a first ball screw and a servo motor, when driving the lifting frame, the servo motor is started to drive the first ball screw which drives the drive rod, and the drive rod drives the lifting frame, then enabling the lifting frame to lift the leveling bracket to lift the leveling bracket. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view showing an overall structure of an all-electric fixed underfloor wheel sets lathe according to an embodiment of the present application; 
         FIG.  2    is another perspective view of the all-electric fixed underfloor wheel sets lathe according to an embodiment of the present application; 
         FIG.  3    is a schematic view showing a configuration of a wheel driving device in the all-electric fixed underfloor wheel sets lathe according to an embodiment of the present application; 
         FIG.  4    is another perspective structural view of the wheel driving device in the all-electric fixed underfloor wheel sets lathe according to an embodiment of the present application, mainly showing a hemispherical groove; 
         FIG.  5    is another perspective structural view of the wheel driving device in the all-electric fixed underfloor wheel sets lathe according to an embodiment of the present application, mainly showing a leveling assembly; and 
         FIG.  6    is a schematic view showing the structure of the wheel axial limiting device in the all-electric fixed underfloor wheel sets lathe according to an embodiment of the present application. 
     
    
    
     Description of reference numerals:  100 , frame;  200 , rail;  300 , lathe tool;  400 , wheel driving device;  410 , leveling bracket;  411 , hemispherical groove;  420 , drive assembly;  421 , friction driving pulley;  422 , second drive motor;  430 , lifting assembly;  431 , lifting frame;  432 , drive structure;  433 , fixed housing;  434 , drive rod;  435 , first ball screw;  436 , servo motor;  437 , pressure sensor;  440 , leveling assembly;  441 , leveling housing;  442 , leveling rod;  443 , second ball screw;  444 , hand-held rod;  445 , receiving cavity;  500 , wheel axial limiting device;  510 , device body;  511 , limiting block;  520 , limiting rod;  521 , placing cavity;  522 , spring;  523 , waist-shaped limiting groove;  530 , limiting pulley;  531 , limiting groove;  540 , push assembly;  541 , third ball screw;  542 , first drive motor;  600 , guide sleeve;  700 , rotation seat; and  800 , wheel. 
     DETAILED DESCRIPTION 
     This application is described in further detail below with reference to  FIGS.  1 - 6   . 
     The embodiments of the present application disclose an all-electric fixed underfloor wheel sets lathe. 
     Referring to  FIGS.  1  and  2   , an all-electric fixed underfloor wheel sets lathe comprises a frame  100 , two rails  200 , two lathe tools  300 , two sets of wheel driving devices  400 , wherein the two rails  200  are provided in parallel and spaced apart. A rail  200 , a lathe tool  300  and a set of wheel driving devices  400  are provided on one side of the frame  100 , and another rail  200 , another lathe tool  300  and another set of wheel driving devices  400  are provided on the other side of the frame  100 . When repairing a wheel  800 , it is driven onto the rail  200  and moved to the top of the wheel driving device  400  which lifts the wheel  800  and then separates the wheel  800  from the rail  200 , and then the wheel driving device  400  drives the wheel  800  to rotate, and the lathe tool  300  repairs the wheel  800 , i.e. the effect of repairing the wheel  800  is achieved. 
     Referring to  FIGS.  1  and  3   , in order to lift the wheels  800  and drive the wheels  800  to rotate, the wheel driving device  400  includes a leveling bracket  410 , a drive assembly  420  provided on the leveling bracket  410 , and a lifting assembly  430  provided at one end of the bottom of the leveling bracket  410 . The lifting assembly  430  is an all-electric cushioning type assembly. The lifting assembly  430  is used to lift one end of the leveling bracket  410 , and the drive assembly  420  is configured for driving the wheel  800  lifted to rotate, i.e., the wheel  800  is lifted and rotated. 
     After lifting the leveling bracket  410  by the lifting assembly  430 , an included angle is formed between the leveling bracket  410  and the central axis of the wheel  800 , so that the contact surface between the drive assembly  420  and the wheel  800  is smaller, so that the pressure at the contact position between the drive assembly  420  and the wheel  800  is greater, thereby resulting in more wear of the wheel  800  by the drive assembly  420 , and finally causing a burden on the repair of the wheel  800 . 
     Referring to  FIGS.  1  and  3   , in order to reduce the occurrence of severe wear of the drive assembly  420  on the wheel  800 , resulting in a burden on the repair of the wheel  800 , the wheel driving device  400  further comprises a leveling assembly  440  provided at the bottom of the leveling bracket  410  and located at an end of the leveling bracket  410  away from the lifting assembly  430 . After lifting the wheel  800 , the leveling assembly  440  is operated to drive the leveling bracket  410  which is gradually in a horizontal state, and then the central axis of the drive assembly  420  is set to be collinear with the central axis of the wheel  800  as far as possible to reduce the occurrence of forming an included angle between the central axis of the drive assembly  420  and the central axis of the wheel  800 , thereby reducing the occurrence of heavy wear of the wheel  800  by the drive assembly  420  and causing a burden on the repair of the wheel  800 . 
     Referring to  FIGS.  1  and  4   , in order to lift the leveling bracket  410 , the lifting assembly  430  comprises a lifting frame  431  and a drive structure  432 , wherein the lifting frame  431  is U-shaped, an opening of the lifting frame  431  faces a leveling bracket  410 , and the lifting frame  431  is hinged to the bottom of the leveling bracket  410 , and the drive structure  432  is fixedly connected to the frame  100 . When the leveling bracket  410  is lifted, the drive structure  432  is operated to drive the lifting frame  431  to lift the leveling bracket  410 , and the lifting frame  431  and the leveling bracket  410  rotate relative to each other, i.e., the leveling bracket  410  is lifted. 
     Referring to  FIGS.  1  and  4   , in order to drive the lifting frame  431 , the drive structure  432  includes a fixed housing  433 , a drive rod  434  provided for a pipe body and having one end slidably coupled in the fixed housing  433 , a first ball screw  435 , and a servo motor  436 . The first ball screw  435  is rotatably connected in the fixed housing  433 , the first ball screw  435  is provided parallel to the drive rod  434 , the nut of the first ball screw  435  is fixedly connected to the drive rod  434 , and the screw of the first ball screw  435  is in a drive connection to the output shaft of the servo motor  436 . The servo motor  436  is fixedly connected to a fixed housing  433  which is fixedly connected to a frame  100 . The drive rod  434  is located at the bottom of the lifting frame  431  and is fixedly connected to the bottom of the lifting frame  431 . When the lifting frame  431  is driven, the servo motor  436  is started to drive the screw of the first ball screw  435  to rotate; the screw of the first ball screw  435  and the nut rotate relative to each other; the nut moves along the length direction of the screw; and at the same time, the nut drives the drive rod  434  to move, i.e., the lifting frame  431  is driven. 
     Referring to  FIGS.  1  and  4   , in order to facilitate a worker in determining the height at which a wheel  800  is lifted, the drive rod  434  is fixedly connected to the lifting frame  431  through a pressure sensor  437  which is fixedly connected to the bottom of the lifting frame  431  and fixedly connected to the top of the drive rod  434 . When a wheel  800  is lifted, the drive assembly  420  gradually abuts against the wheel  800 , and as the height of the wheel  800  being lifted increases, the pressure experienced by the pressure sensor  437  increases. When the pressure experienced by the pressure sensor  437  no longer changes, the lifting of the wheel  800  is discontinued, indicating that the wheel  800  has disengaged from the rail  200 , thereby facilitating a worker to determine a height at which the wheel  800  has been lifted. 
     With reference to  FIGS.  1  and  4   , in order to increase the stability when the lifting frame  431  and the leveling bracket  410  rotate relative to each other, one end of the lifting frame  431  away from the drive rod  434  is provided in a hemispherical shape, the bottom of the leveling bracket  410  is provided with a hemispherical groove  411  corresponding to the lifting frame  431 , and one end of the lifting frame  431  in a hemispherical shape is inserted into the hemispherical groove  411 . When the lifting frame  431  drives the leveling bracket  410 , one end of the lifting frame  431  in a hemispherical shape rotates in the hemispherical groove  411 , thereby reducing the occurrence of separation between the lifting frame  431  and the leveling bracket  410 , and further increasing the stability when the lifting frame  431  and the leveling bracket  410  rotate relative to each other. 
     Referring to  FIGS.  1  and  5   , in order to level the leveling bracket  410 , the leveling assembly  440  comprises a leveling housing  441 , a leveling rod  442 , a second ball screw  443  and a hand-held rod  444 , wherein one end of the leveling rod  442  is provided with a receiving cavity  445 , and one end of the leveling rod  442  provided with the receiving cavity  445  is slidably connected in the leveling housing  441 . One end of the second ball screw  443  is rotatably connected in the leveling housing  441 , one end of the screw of the second ball screw  443  is inserted into the receiving cavity  445 , and the nut of the second ball screw  443  is fixedly connected to the cavity port in the receiving cavity  445 . The hand-held rod  444  is vertically fixedly connected to an end of the screw of the second ball screw  443  outside the leveling housing  441 . The leveling housing  441  is fixedly connected to the frame  100 , and the leveling rod  442  is hinged to an end of the leveling bracket  410  away from the lifting frame  431 . 
     When the leveling bracket  410  is leveled, the hand-held rod  444  is rotated; the hand-held rod  444  drives the screw of the second ball screw  443  to rotate; the screw of the second ball screw  443  and the nut rotate relatively; the nut moves along the length direction of the screw; at the same time, the nut drives the leveling rod  442 ; the leveling rod  442  drives the leveling bracket  410 ; and the leveling bracket  410  and the leveling rod  442  rotate relatively, so that the leveling bracket  410  is gradually in a horizontal state, thereby achieving the effect of leveling the leveling bracket  410 . 
     During rotation of a wheel  800  by the drive assembly  420 , the wheel  800  may move in its own axial direction, which in turn makes repair of the wheel  800  by the lathe tool  300  less efficient. 
     Referring to  FIGS.  1  and  6   , in order to reduce the movement of a wheel  800  in its own axial direction and improve the repair efficiency of the lathe tool  300  to the wheel  800 , the all-electric fixed underfloor wheel sets lathe further comprises a wheel axial limiting device  500  provided in two sets, including one set of the wheel axial limiting devices  500  provided on one side of the frame  100 , and the other set of the wheel axial limiting devices  500  provided on the other side of the frame  100 . When the wheel  800  is axially limited, the two sets of wheel axial limiting devices  500  respectively interfere with the inner sides of the two wheels  800 , and the two sets of wheel axial limiting devices  500  are both configured for axially limiting the wheel  800  to reduce the movement of the wheel  800  in the axial direction thereof when the wheel  800  rotates, thereby increasing the stability of the wheel  800  when it rotates, thereby improving the repair efficiency of the lathe tool  300  for the wheel  800 . 
     Referring to  FIGS.  1  and  6   , in order to achieve axial limiting of a wheel  800 , each set of wheel axial limiting devices  500  comprises a device body  510 , a limiting rod  520 , a limiting pulley  530  and a pushing assembly  540 , wherein the limiting pulley  530  is provided with a limiting groove  531  provided along the circumferential direction of the limiting pulley  530 . A limiting pulley  530  is provided at one end of the limiting rod  520 , and the limiting pulley  530  is rotatably connected to the limiting rod  520 . An end of the limiting rod  520  away from the limiting pulley  530  is slidably connected in the device body  510 , and the pushing assembly  540  is provided on the device body  510 , and the device body  510  is fixedly connected to the frame  100 . After a wheel  800  is separated from the rail  200 , the pushing assembly  540  is operated to drive the limiting rod  520  which drives the limiting pulley  530  to move, the limiting pulley  530  moves in a direction close to the wheel  800 , and then the limiting pulley  530  gradually abuts against the wheel  800 , and the limiting groove  531  abuts against the rim of the wheel  800 . When the drive assembly  420  drives the wheel  800  to rotate, the limiting pulley  530  rotates with the rotation of the wheel  800 , and the two limiting pulleys  530  respectively apply forces in opposite directions to the two wheels  800 , i.e. the two wheels  800  are axially limited. 
     Referring to  FIGS.  1  and  6   , in order to push the limiting rod  520 , the pushing assembly  540  includes a third ball screw  541  and a first drive motor  542 , and an output shaft of the first drive motor  542  is fixedly connected coaxially with a screw of the third ball screw  541 . The third ball screw  541  is located in the device body  510 , the screw of the third ball screw  541  is provided coaxially with the limiting rod  520 , one end of the limiting rod  520  located in the device body  510  is provided with a placing cavity  521  accommodating the third ball screw  541 , one end of the screw of the third ball screw  541  penetrates into the placing cavity  521 , and a nut of the third ball screw  541  is fixedly connected to a cavity port of the placing cavity  521 . The first drive motor  542  is fixedly connected to the device body  510  which is fixedly connected to the frame  100 . When the limiting rod  520  is pushed, the first drive motor  542  is started to drive the screw rod of the third ball screw  541  to rotate; the screw rod of the third ball screw  541  and the nut rotate relative to each other; the nut moves along the length direction of the screw rod; and the nut drives the limiting rod  520  to move, i.e., the limiting rod  520  is pushed. 
     When the limiting pulley  530  limits a wheel  800 , the wheel  800  applies a force perpendicular to the length direction of the limiting rod  520  to the limiting pulley  530 , which causes the limiting rod  520  to bend. In order to reduce the occurrence of easy bending of the limiting rod  520 , an outer sleeve of the limiting rod  520  is provided with a guide sleeve  600  having one end inserted into the device body  510  and slidably coupled with the device body  510 . When the pushing assembly  540  drives the limiting rod  520 , the limiting rod  520  slides relative to the device body  510 , and the guide sleeve  600  moves with the movement of the limiting rod  520 , so that the guide sleeve  600  enhances the strength of the limiting rod  520 , thereby increasing the maximum lateral pressure that the limiting rod  520  can bear, thereby reducing the occurrence of bending the limiting rod  520 . 
     Referring to  FIGS.  1  and  6   , in order to achieve that the guide sleeve  600  moves with the movement of the limiting rod  520 , the diameter of the limiting rod  520  near the end of the limiting pulley  530  is smaller than that of the limiting rod  520  away from the end of the limiting pulley  530 . An aperture of a central hole of the guide sleeve  600  near the end of the limiting pulley  530  is smaller than that of the central hole of the guide sleeve  600  away from the end of the limiting pulley  530 . A spring  522  is sleeved on the limiting rod  520 , one end of the spring  522  abuts against an end of a thicker end of the limiting rod  520 , and the other end of the spring  522  abuts against an end wall of the thicker end of the central hole of the guide sleeve  600 . When the limiting rod  520  moves, the limiting rod  520  drives the spring  522  to move, so that the guide sleeve  600  moves with the movement of the limiting rod  520  under the action of the spring  522 , i.e., the guide sleeve  600  moves with the movement of the limiting rod  520 . 
     Referring to  FIGS.  1  and  6   , in order to increase the effect of axially limiting a wheel  800  by a wheel axial limiting device  500 , a circumferential side surface of the guide sleeve  600  is provided with a waist-shaped limiting groove  523 , the length direction of which is parallel to the axial direction of the guide sleeve  600 . A limiting block  511  is fixedly connected to the device body  510 , one end of the limiting block  511  is inserted into the device body  510 , and the other end of the limiting block  511  is located in the waist-shaped limiting groove  523 . The limiting pulley  530  is rotatably connected to the limiting rod  520  via a rotation seat  700 ; the limiting pulley  530  is rotatably connected to the rotation seat  700  which is hinged to the limiting rod  520 ; and one end of the rotation seat  700  near the limiting pulley  530  is hinged to the guide sleeve  600 . 
     When the limiting rod  520  moves, the guide sleeve  600  moves with the movement of the limiting rod  520 , and the limiting block  511  slides relative to the waist-shaped limiting groove  523 . When the limiting block  511  abuts against an end wall of the waist-shaped limiting groove  523 , the guide sleeve  600  stops moving, the limiting rod  520  continues moving, the limiting rod  520  compresses the spring  522 , the limiting rod  520  drives the rotation seat  700 , the rotation seat  700  and the guide sleeve  600  rotate relative to each other, and the rotation seat  700  drives the limiting pulley  530  to rotate until the limiting groove  531  abuts against the rims of the wheels  800 . At this moment, an included angle is formed between the rotation axis of the limiting pulley  530  and the rotation axis of the wheel  800 , and this state can increase the limiting effect of the limiting pulley  530  on the axial direction of the wheel  800 . 
     Referring to  FIGS.  1  and  3   , finally, in order to drive the wheels  800 , the drive assembly  420  includes two friction driving pulleys  421  and two second drive motors  422 , and one second drive motor  422  is provided corresponding to one friction driving pulley  421 . Each second drive motor  422  is in a drive connection to a corresponding friction driving pulley  421 . The friction driving pulleys  421  on the two sets of drive assemblies  420  are oppositely provided. The friction driving pulleys  421  are rotatably connected to the leveling bracket  410 , and the second drive motor  422  is fixedly connected to the leveling bracket  410 . After the wheels  800  move onto the rail  200 , they are positioned on top between two friction driving pulleys  421  on the same set of drive assemblies  420 . When driving the wheels  800 , the friction driving pulleys  421  abut against the wheels  800 , the second drive motor  422  drives the friction driving pulleys  421  which drive the wheels  800 , i.e., the wheels  800  are driven. 
     The implementation principle of an all-electric fixed underfloor wheel sets lathe of the embodiments of the present application is as follows: when repairing the wheels  800  using the all-electric fixed underfloor wheel sets lathe, the wheels  800  are first moved onto the rail  200  of the all-electric fixed underfloor wheel sets lathe. A servo motor  436  is then started, which in turn causes the drive rod  434  to drive the lifting frame  431  which rotates relative to the leveling bracket  410  and leveling bracket  410  is lifted, the friction driving pulleys  421  abut against the wheels  800  and lift the lifting wheels  800  off from the rail  200 . 
     The hand-held rod  444  is rotated, so that the leveling rod  442  drives the leveling bracket  410 , and the leveling bracket  410  is gradually in a horizontal state to ensure the contact area between the friction driving pulleys  421  and the wheels  800  as far as possible, and reducing the occurrence of additional wear on the wheels  800  due to the smaller contact area between the friction driving pulleys  421  and the wheels  800 . 
     Then, the first drive motor  542  is started again, so that the limiting rods  520  drive the limiting pulleys  530  toward the wheels  800 , and finally the limiting groove  531  abuts against rims of the wheels  800 . Finally, the second drive motor  422  is started to drive the friction driving pulleys  421  to drive the wheels  800  to rotate, and the lathe tool  300  repairs the wheels  800 . 
     The above-mentioned preferred embodiments of the present application do not limit the scope of protection of the present application, and therefore: all changes which come within the meaning and range of equivalence of the claims are to be embraced within their scope.