Bogie with improved secondary suspension system, and railway vehicle comprising such bogie

Abstract

A bogie for a railway vehicle includes a frame, which has a first side beam and a second side beam extending along a longitudinal axis of the bogie and spaced apart from each other. A secondary suspension system is located on the frame and includes a first suspension assembly, which includes a first air spring and a first auxiliary spring positioned at the first side beam. The first air spring is positioned below and is arranged to be pressurized for supporting the body of the railway vehicle above the frame. The first auxiliary spring is fixed to an upper side of the first side beam underneath and spaced apart from the first air spring. The first suspension assembly further includes a first force-transmission mechanism configured to transmit forces exerted by the body on the first air spring to the frame via the first auxiliary spring.

What is claimed is: 
     
         1 . A bogie for a railway vehicle, comprising:
 a frame comprising at least a first side beam and a second side beam which extend along a first longitudinal axis of the bogie spaced apart from each other;   a secondary suspension system which is located on the frame and comprises at least a first suspension assembly, said first suspension assembly including a first air spring and a first auxiliary spring which are positioned at said first side beam, wherein the first air spring is positioned below and is arranged to be pressurized for supporting the body of the railway vehicle above the frame;   wherein the first auxiliary spring is fixed to an upper side of said first side beam underneath and spaced apart from the first air spring;   and wherein the first suspension assembly further comprises at least a first force-transmission mechanism which is configured to transmit forces exerted by the body on the first air spring to the frame via the first auxiliary spring.   
     
     
         2 . The bogie according to  claim 1 , wherein said first side beam comprises a through cavity which extends along a second substantially vertical axis transversal to said first longitudinal axis and is adapted to house at least part of said first force-transmission mechanism. 
     
     
         3 . The bogie according to  claim 2 , wherein said first force-transmission mechanism comprises first hydraulic means which are housed at least partially inside said through cavity. 
     
     
         4 . The bogie according to  claim 3 , wherein said first force-transmission mechanism comprises a supporting body which includes at least:
 a head which is positioned above and arranged to bear against an upper surface of the first auxiliary spring; and   a shank having a port, and a piping connection which extend, at least partly, within the first auxiliary spring, from said head downwardly along said substantially vertical axis into said through cavity towards an end bottom side of the supporting body.   
     
     
         5 . The bogie according to  claim 4 , wherein said hydraulic means comprise at least:
 a hydraulic chamber which is partially filled with a fluid and is placed together with said port and the piping connection of the supporting body at least partly inside said through cavity; and   a piston which is connected to a rod, said piston being inserted in said hydraulic chamber sliding along said second substantially vertical axis.   
     
     
         6 . The bogie according to  claim 4 , wherein a first predetermined gap, measured along a third substantially horizontal axis transversal to said first longitudinal axis and said second substantially vertical axis, is defined between the external surface of the shank and an internal surface of the first side beam delimiting said through cavity. 
     
     
         7 . The bogie according to  claim 4 , wherein said supporting body includes a substantially central through cavity which extends, along said second substantially vertical axis, from said head up to an end bottom side of the shank. 
     
     
         8 . The bogie according to  claim 5 , wherein said central through cavity of the supporting body includes a lower part which is located, at least partly, within said through cavity of the first side beam and forms said hydraulic chamber. 
     
     
         9 . The bogie according to  claim 8 , wherein said central through cavity of the supporting body includes an upper part which is located at a space comprised between the upper side of the first side beam and the first air spring, and wherein a portion of said rod extends and is movable inside said upper part. 
     
     
         10 . The bogie according to  claim 9 , wherein said first force-transmission mechanism further comprises a rim which extends from a top plate of the first air spring downwardly along said second substantially vertical axis inside said upper part of the central through cavity of the supporting body. 
     
     
         11 . The bogie according to  claim 10 , wherein said rim comprises, at a bottom end thereof, a recess adapted to receive inside an end portion of said rod, said recess having a base surface into contact with an upper head surface of the rod. 
     
     
         12 . The bogie according to  claim 11 , wherein said recess comprises a side wall which protrudes from said base surface so that a second predetermined gap, measured along a third substantially horizontal axis transversal to said first longitudinal axis and said second substantially vertical axis, is defined between the external surface of the rod and an internal surface of the side wall itself. 
     
     
         13 . The bogie according to  claim 1 , wherein the secondary suspension system further includes a second suspension assembly which is positioned at said second side beam, said first and second suspensions assemblies being in fluid communication to each other via a connecting pipe so that to balance between them at least vertical forces exerted by the body of the railway vehicle on said first and second side beams. 
     
     
         14 . The bogie according to  claim 13 , wherein the secondary suspension system further includes a fluid reservoir which contains a fluid and is connected to and supplies said connecting pipe with said fluid. 
     
     
         15 . A railway vehicle comprising at least one bogie according to  claim 1 . 
     
     
         16 . The bogie according to  claim 7 , wherein said central through cavity of the supporting body includes a lower part which is located, at least partly, within said through cavity of the first side beam and forms said hydraulic chamber. 
     
     
         17 . The bogie according to  claim 16 , wherein said central through cavity of the supporting body includes an upper part which is located at a space comprised between the upper side of the first side beam and the first air spring, and wherein a portion of said rod extends and is movable inside said upper part. 
     
     
         18 . The bogie according to  claim 17 , wherein said first force-transmission mechanism further comprises a rim which extends from a top plate of the first air spring downwardly along said second substantially vertical axis inside said upper part of the central through cavity of the supporting body. 
     
     
         19 . The bogie according to  claim 18 , wherein said rim comprises, at a bottom end thereof, a recess adapted to receive inside an end portion of said rod, said recess having a base surface into contact with an upper head surface of the rod. 
     
     
         20 . The bogie according to  claim 19 , wherein said recess comprises a side wall which protrudes from said base surface so that a second predetermined gap, measured along a third substantially horizontal axis transversal to said first longitudinal axis and said second substantially vertical axis, is defined between the external surface of the rod and an internal surface of the side wall itself.