Load power takeoff (PTO) device for high-lift portal crane

Abstract

The invention provides a load power takeoff (PTO) device for a high-lift portal crane. The PTO device comprises a tension sensor and a stress release device for fixing a hoisting rope. The stress release device comprises a crossbeam, a thrust ball bearing, a rotating joint and a standard wire rope sling, wherein, the standard wire rope sling is fixedly connected below the rotating joint, the thrust ball bearing is arranged between the rotating joint and the crossbeam, the rotating joint is fixedly connected with the crossbeam in a free rotation manner, and two ends of the crossbeam are connected with the tension sensor through a pulling plate; and output of the tension sensor is connected to a main machine of a moment limiter in a cab of the crane. The load PTO device has the advantages that load measurement accuracy is improved and wear of the wire rope is reduced in the case of load hoistingzmeasurement; and a wire rope fixing device is equipped with the thrust ball bearing which can bear load and freely rotate so that errors in a PTO signal caused by the internal rotating force of the wire rope can be rapidly relieved by means of a stress release function, thus avoiding frequent operation of a protective device of the portal crane resulting from run-out tolerance of critical load weight.

Description

technical field [0001] The invention belongs to the technical field of hoisting machinery, in particular to a load power take-off device of a high-lift portal crane, which is a supporting device of the crane equipment. By connecting the force sensor in series with the wire rope, the load signal is directly obtained from the force of the wire rope and transmitted back to the main engine of the torque limiter to complete the calculation and confirmation of the hoisting load. Background technique [0002] At present, most of the power take-off methods for hoisting heavy loads of domestic gantry cranes, especially the non-single-rate hoisting mechanisms, mostly adopt the three-pulley type power take-off method, that is, install them on both sides of the hoisting wire rope where the hoisting wire rope passes. There are a total of three pulleys, and the sensor is elastically deformed by the side pressure generated by the steel wire rope during hoisting. This method has the followi...

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Problems solved by technology

[0003] (1) The steel wire rope always produces rolling friction with these pulleys, which affects the efficiency of the lifting mechanism and increases the wear of the steel wire rope;

[0004] (2) Since the signal acquisition method is not direct enough, the error of all data is often too large

[0005] However, if the tension sensor is directly used to take force at the end of the hoisting wire rope, in the high-lift portal machine, with the rapid lifting of the hook, the entire hoisting wire rope will accumulate a lot of internal force in the entire lift. If it is effectively released, it is easy to cause several steel wire ropes to twist together when encountering unbalanced lifting weight or external force. The consequences are firstly to cause great damage to the steel wire rope, and secondly to easily cause severe overloading of the tension sensor. until failure

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