Hosted cable hanging device of a pair of is 90 ° of supports axis, can guarantee overhead part of parts does not in tower frame swing Shi tilt, tower frame bottom of radial joint bearing, can avoid tower frame longitudinal swing Shi produced bent stress and the supplement tours tower frame of installed location errors, tower frame tower head and top Department of hanging pulley bracket can around supports axis swing, to reduces up rose cable and traction cable from hanging pulley rope slot in the leads of deflection angle.
Tower frame is pendulum Tower type cable crane and other type cable crane differences maximum of part, dang tower frame swing Shi, at tower frame tower head Shang of hosted cable hanging device led overhead part (including hosted cable, and up rose cable and traction cable and oriented pulley, and bearing horse, and lifting car, part) swing, if overhead part with tower frame of swing and deflection, is cable machine on cannot normal work, and three gorges pendulum Tower type cable crane tower frame of section smaller, tower frame of total height over 150m[1], design process in the should full consider work Shi (especially pendulum Tower Shi) may appears of tower frame twist phenomenon. Three-Gorge luffing cable crane in the head, the top of the tower and base parts adopts the adjustments, anti-torsion and back tour structure, so that the work does not twist the Tower, swing-Tower in the process of aerial parts of parts not deflect, and may reduce the lifting cable traction cables and leads from the bollard Groove angle and prevent them from job hopping.
1. characteristics of the structure of the Tower of the tower head
Three Gorges pendulum Tower type cable crane tower frame, dang pendulum Tower type cable machine of tower frame swing Shi, at tower frame tower head Shang of hosted cable hanging device led overhead part (including hosted cable, and up rose cable and traction cable and oriented pulley, and bearing horse, and lifting car, part) swing, to guarantee overhead part of parts not with tower frame of swing and tilt, hosted cable hanging device through pair in space Shang is 90 ° of axis and the bearing supporting in tower head Shang, to avoid manufacturing errors of effect, longitudinal hanging axis (its axis at tower frame of longitudinal Center surface, is main, and Vice Tower tower frame vertical Shi its center line joint into of plane Shang) of supporting bearing 2 for can adjustable heart bearing (code for 24056CC/W33), thrust adjustable heart roll child bearing 4 (code for 29464E) bear entire overhead part of longitudinal load. Vertical suspension shaft through the axis plate fixed to the tower head on a support plate welded together, relying on the aerial Component of gravity-swing portrait hanging around a box-axis rotation, ensure that the various parts of the aerial parts are basically in a constant state of vertical, lateral suspension shaft bearing with radial spherical plain bearings.
Transverse hanging axis and Qian, and Hou pulled plate connection axis selection joint bearing of main role is elimination hosted cable hanging device of manufacturing and the installed errors of effect, avoid before and after pulled plate upper and lower swing Shi “forced effort”; in addition, due to longitudinal hanging axis by by of load larger, in actual work in the sometimes its supports bearing of turns does not flexible, appears tower frame first swing a angle Hou longitudinal swing box then rotating of lag, and on both sides of tower frame hanging device of swing box swing does not synchronization of phenomenon, selection joint bearing can avoid this lag and due to hosted cable in installed using process in the produced of torque of effect, and can supports side to force, dang on both sides of tower frame hanging device of swing box swing different step Shi can prevent hosted cable by twist.
Dang tower frame swing Shi, supporting in hosted cable hanging device Shang of traction cable hanging pulley follow tower head together swing, and traction cable Xia support from machine room leads Hou (its leads line and tower frame swing of axis basic parallel), required after fixed in ground of oriented pulley (its axis line and cable crane of longitudinal axis basic parallel) oriented [1], therefore tower head traction cable hanging pulley and fixed in tower frame bottom of traction cable oriented pulley between of a traction cable will appears oblique pull phenomenon, to reduces traction cable access pulley of deflection angle, to reduce traction cable and oriented pulley of wear, and prevent traction cable hopping, hanging pulley bearing through hanging axis and bearing supporting in hosted cable hanging device Shang, once traction cable oblique pull can through hanging axis of swing adjustment, because supporting axis Shang bear of axis to load larger, so selection cone roll child bearing (code for 32,222) and thrust adjustable heart roll child bearing (code for 29320E). Hoisting rope in the tower head hanging pulley bearing structure and the same. This structure, Tower swing towing (lifting cables) when the stay, only at the ground guide pulley cable’s angle changes, and less angular, thus not support shaft of the steering wheel on the ground that need to be designed to swing.
Main tower of the luffing cable cranes and the Deputy Head of Tata carrying rope suspension equipment in addition to differences in structure and size of the front suspension, and the Deputy Tower without lifting rope suspension pulleys and bearing, a structure of other parts of the same.
2. characteristics of structure at the bottom of the Tower
Tower frame bottom of supporting bearing bear was entire tower frame of weight and the tower frame Shang down of vertical load, by by load larger, pendulum Tower type cable crane of tower frame not only need around its supporting axis in Shang downstream direction swing, and work Shi because load of changes, dang hosted cable vertical of changes Shi, will caused tower frame longitudinal of swing, if tower frame bottom of supporting used axis, and bushings structure, tower frame longitudinal deflection Shi will produced bending moment (bottom bending moment maximum), and bent deformation, and in section Shang produced bent stress, need increases Tower frame of section, also, ideal status Xia, tower frame cross section of longitudinal axis should and cable crane axis (is tower frame vertical Shi hosted cable of axis), and tower frame vertical Shi of Hou cable of axis in a lead vertical surface Shang, but because actual manufacturing and the installation errors, these axis inevitable of will appears deflection, this deflection will in tower frame Shang produced torque, because pendulum Tower type cable crane tower frame of section smaller, its long fine than broad Yu other type cable type crane of tower frame, anti-twist ability low, by produced of torque will will serious effect tower frame of stability even makes pendulum Tower type cable crane cannot normal work. So tower frame bottom of supporting bearing also for radial joint bearing (radial-spherical plain bearing), its structure see Figure 3, bore (is axis diameter) d=420, by Sweden SKF bearing company manufacturing, SKF company set of code for SKF-BLRB364840A. Joint bearing not only can bear larger of surface work pressure, and allows axis and shell hole of axis has larger of relative skew, to avoid tower frame longitudinal swing Shi tower frame Shang produced bending moment, and can avoid tower frame cross section of longitudinal axis, and cable crane axis, and Hou pull cable axis deflection Shi tower frame Shang produced torque. In addition, after the Tower adopts joint bearing at the bottom, make the bottom of the tower or vertically or horizontally, have become an ideal hinge structure, force clearer (static structure), the design is simple, convenient and safe.
Through tower frame tower head Shang of four root pendulum Tasso, can prevent tower frame of upper twist, because tower frame bottom of supporting bearing for radial joint bearing, it can around tower frame of axis Z-Z rotation, thus cable crane work Shi will caused tower frame bottom of twist, therefore, in cable crane lower of upgrade framework [2] base and ground between set has anti-twist device, its detail structure schematic see Figure 4, anti-twist sliding block of connection axis of axis should and supporting bearing in same line Shang, so as not to effect tower frame of swing, dang tower frame longitudinal swing Shi sliding block can in fixed guide slot Shang upper and lower sliding, sliding block of material for engineering plastics (is nylon), has must of buffer effectiveness.
Torsion-proof device should be in the Tower (including the carrying rope) installed after the installation is complete, to eliminate the Tower cross section of the vertical axis and axis deflection error influence of cable crane, avoiding torsion-proof device producing prestressed and Tower on torsion.
3. characteristics of structure at the top of the Tower
Pendulum Tower type cable crane tower frame of top Department installation has traction cable Shang support hanging pulley (is days wheel) of bracket, and tower head Shang of hanging pulley similar, if the bracket for fixed supporting, is Dang tower frame swing deflection Shi, will will makes days wheel and fixed in tower frame bottom of traction cable oriented pulley between of traction cable oblique pull, increased traction cable and days wheel of wear, reduce they of using life. The bracket by the steel welded together, its structure is shown in Figure 5, figure lock nut up and down in the two, and locking nut also check plate above, to ensure that the support shaft bracket is not loose. When you swing deflected the Tower through the bracket swing, you can make between the top and bottom of the tower lead block reduces the amount of traction cable-stayed. Swing another role for the wheel bracket is to compensate for its manufacture, and installation errors, as well as the main sync swing angle arising out of the Tower of the tower.
Also, Tower platform Shang also has a can for 360 ° rotating, and lifting ability for 25KN of suspended arm Rotary hanging machine, its lifting height for 153m, main for cable crane maintenance maintenance process in the hanging games material and the device, because the hanging machine at cable crane tower frame of Supreme location, dang tower frame used top rose of method installation (demolition) Shi [2], hanging machine may also in cable crane installation and the demolition of process in the using.
4. closing remarks
Part three-Gorge luffing cable crane for overhead on flying devices through a pair of space was 90 ° for shaft and bearing on the Tower’s head, to ensure that the various parts of the aerial parts will not be deflected with the swing of the tower. Because hosted cable of tension larger (maximum tension up 4080kN), is hanging axis supporting bearing of load larger, and tower frame swing of range little, the supporting bearing of rotation range little, and rotation speed slow, therefore the supporting bearing in rotation of process in the, sometimes will appears Peristaltic phenomenon and the issued “squeaking” of sound, especially in cable crane run of early, in strengthening has on bearing, parts of lubrication, and cable crane run has a time Hou this phenomenon basic disappear. In addition, sometimes bearing rotating lag somewhat behind the swinging of the Tower, Tower during the swing, hanging plate angle and vertical changes of no more than 1 °. Under three gorges pendulum Tower type cable crane in three gorges engineering in the of using situation confirmed, appears above phenomenon does not effect overhead part of normal using, hosted cable also not appears relaxation and broken silk, tower head traction cable and lifting cable of oriented pulley bearing, and and days wheel bracket of work situation good, not occurred traction cable and up rose cable hopping phenomenon, Tower Rotary hanging machine in cable crane of installation and demolition, and run maintenance and the overhead part fault processing of process in the are play has important of role, tower frame bottom of supporting bearing running flexible, anti-twist device can effective of prevent tower frame twist, tower frame of stability better.