CN1895987A

CN1895987A - Resolution for damaging railings by heavy bridge or gate crane

Info

Publication number: CN1895987A
Application number: CN 200610100439
Authority: CN
Inventors: 王钢
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-06-29
Filing date: 2006-06-29
Publication date: 2007-01-17

Abstract

A scheme for preventing the damage of the bridge (or gantry) crane's big carriage to track, the cracking of the welded position on main beam and end beam and the horizontal deformation of carriage body, which are caused by speed difference of two three-phase asymmetrical motors at both sides of said big carriage features that two speed regulator units with closed-loop function are used to respectively control said two asymmetrical motors, resulting in stable running.

Description

The resolution that bridge, transfer crane cart are gnawed

Technical field under in the of one:

Mechanical drive and control.

Two background technologies:

Crane in bridge type, transfer crane when cart moves if the effect of the horizontal side force that is subjected to, when operation big car body horizontal deformation (deflection that comprises relative deformation with the relative big Car Track of car load of big car body self structure) taking place and makes the operation of the big relatively Car Track generation of big wheel lateral deviation caused, big wheel its wheel rim when operation continues to contact the phenomenon that produces skimming wear with the side of track and claims to gnaw, and claims again to gnaw rail, sting.This defective not only can make big wheel and track early failure, and big car body is crooked when operation, the distortion meeting damages the metal construction of car body, and the overhead traveling crane chance can pass to factory building to car body crooked horizontal side force that produces when moving, and so just the stability to factory building also constitutes a threat to.The defective that bridge, transfer crane cart are gnawed is obstinate common disease.The designing unit of hoisting crane generally takes to control simultaneously with a cover speed regulation device method of the asynchronous dynamo on corresponding both sides now.But can not disclose and solve the differential problem of cart both sides motor, the horizontal side force that differential brought is to produce the distortion in the horizontal direction of big car body and the basic reason of destruction.

Three summary of the invention:

Horizontal side force can be caused by multiple reason, but modal in actual use reason is because inconsistent the causing of rotating speed of the three phase asynchronous motor of drive axle, transfer crane cart both sides.The three phase asynchronous motor of cart both sides is during by a power supply (as a pressure-speed regulating device etc.) power supply, we only see from the mechanical characteristic (Fig. 1) of three-phase wound-rotor asynchronous motor: the rotating speed and the load of three phase asynchronous motor are inversely proportional to, rotor resistance value big more (rotor loading is big more), slip is just obvious more.Three phase asynchronous motor when the cart both sides (is similar to and thinks that the quality of crane span structure is uniform) when dolly departs from span centre, will be subjected to producing corresponding rotating speeds and change, make the big relatively Car Track of the big wheel that is fixed on the big car body to low speed side occurred level deflection from the different support reaction effect of the big Car Track in both sides; The crane span structure of large span will flexiblely be out of shape under the transverse force effect, though the horizontal rigidity of crane span structure also can retrain the rotating speed of the three phase asynchronous motor of a quick side, also drive simultaneously the rotating speed of the three phase asynchronous motor of a side at a slow speed and both sides are tended to be balanced, but offset the speed discrepancy of both sides three phase asynchronous motor with the rigidity of damaging crane span structure, will certainly cause metal construction easily in some defectives such as stress concentration position cracking and cart rotation browsing roads.So the big more just balanced capacity between the electrical motor of apparent more cart both sides of the span of bridge, transfer crane is important.

Four description of drawings:

Fig. 1 is the three-phase wound-rotor asynchronous motor mechanical characteristic; Fig. 2 is that four wound-rotor asynchronous motors that drive cart both sides (limit) respectively carry out the closed loop control scheme drawing by a cover stator voltage and speed governing by transistor device, and wherein: M1, M2 are the drive motor of cart one side, and M3, M4 are the drive motor of cart opposite side.

Five specific embodiment:

Separately-driven cart dragging system, every limit should have independently frequency converter or independently stator voltage and speed governing by transistor device the cart asynchronous motor is carried out closed loop control, promptly carry out the scheme that drags on " one-to-one limit ".The asynchronous dynamo on cart both sides is in the continuous process near same given expected value, do not have too big commentaries on classics degree fluctuation, so the asynchronous dynamo on both sides always can have soon mutually, slow, from seeking balance, crane span structure moves just steady like this under the constraint of crane span structure horizontal rigidity.

Claims

Bridge, transfer crane are when the design of cart dragging system, and each carries out closed loop control by a cover speed regulation device three phase asynchronous motor of cart both sides.