The type of equipment failure caused by bearing misalignment and the complete crane safety inspection management system

　　<XNUMX> Type of equipment failure caused by bearing misalignment

　　(1) Due to bearing misalignment, the load distribution of each bearing and the dynamic characteristics of the bearing change, which affects the stability of the entire rotor-bearing system;

　　(2) Due to the change of the supporting load, the critical speed of the shafting changes, and the structure resonance is excited;

　　(3) The vibration shape of the shaft system changes under the working speed due to the change of the supporting load, and the weight becomes sensitive under the changing vibration shape under a certain vibration shape, or vice versa;

　　(4) Bearing misalignment leads to uneven clearance of the steam seal of the high-pressure steam turbine and induces clearance excitation;

　　(5) A pair of misaligned bearings, the oil film of the bearing with a large load presents a larger non-linearity, under the effect of the unbalanced disturbing force, the sub-harmonic response and the high-order harmonic response of the shaft vibration can be caused under the conditions :

　　(6) Bearing misalignment causes the bearing to be externally preloaded, which is an alternating force applied to the rotating shaft through the plum-shaped elastic coupling, which can cause fatigue cracks at the coupling section in severe cases;

　　(7) Due to the misalignment of the bearing, the rotor produces low-frequency vortex. The vortex displacement of the shaft and the periodic bending of the rotor produce alternating stress. The frequency of this alternating stress is equal to the difference between the rotation frequency and the vortex frequency. At a certain value, fatigue cracks will occur where the shaft stress is greater.

　　The driving system of the hoisting operation includes the mechanism system and the component system, which are used for the lifting operations.According to the characteristics of the general hoisting mechanism, it can be divided into the hoisting mechanism, the trolley operating mechanism, the large cart operating mechanism and the pitching mechanism. The hydraulic system (including the telescopic rotation of the spreader, the cabin protection, etc.) and the rope supporting mechanism are also the parts with more failures. , The configuration status of the emergency organization is the emergency operation of the corresponding organization.The main components of each operating mechanism are mainly composed of brakes, reducers (gears), couplings, bearings, pulleys, etc. In addition, the lifting, pitching and traction trolley operating mechanisms are also composed of drums, wire ropes, etc., and large and small vehicles run The mechanism also consists of wheels.

　　<XNUMX>, establish a perfect crane inspection management system

　　1. Establishment of monitoring management system

　　The construction and improvement of the management system is an important foundation for the inspection of construction cranes.The prerequisite for the establishment of the lifting machinery system should be the actual application of the construction environment and use methods of the lifting machinery, the content and inspection standards of the inspection work should be clarified for the lifting machinery, and the relevant standards for the data inspection and operation of the lifting machinery should be stipulated in writing. Only by making detailed regulations, the inspectors can be justified in the inspection work, and the inspection work of the lifting machinery can be added, and the inspection effect can also be significantly improved.

　　2. Regularly check the lifting machinery

　　Lifting machinery belongs to special equipment, and the installation, maintenance and performance of lifting machinery are inseparable from the use of lifting machinery. The inspection and certification of lifting machinery by gear couplings will be carried out by related testing departments. Strict training is the basis of inspectors' work, and inspectors can only carry out inspections and issue inspection reports after they have obtained the crane inspector certificate issued by the provincial and above departments.During the normal use of hoisting machinery, regular inspections are required. Tower cranes are required once a year, and bridge gantry cranes are required once every two years. Lifting machinery needs to be inspected again after reinstallation, transformation and overhaul. jobs.The hoisting machinery that has been idle for a long time needs to be inspected, and its circuits and electrical protections, devices, and main stressed components are tested. Only the inspected hoisting machinery can be put into use.

　　3. Supervision and inspection of hoisting machinery products

　　As one of the special machinery, the relevant manufacturing unit should self-inspect the products produced and strictly enforce the quality of the products. The application for technical inspection to the local provincial management and inspection department is done after self-inspection.

　　The technical requirements of hoisting machinery, the review of materials of the hoisting machinery and the performance of the control system are the main content of the indispensable testing, and the no-load and load tests should also be carried out on the hoisting machinery.Companies that use lifting machinery should review the relevant qualifications of the manufacturing unit when purchasing lifting machinery, conduct strict inspections on the quality of related products, and compare them with different manufacturers of the same product. Before the construction site, the machinery should also be strictly inspected. The equipment entering the construction site can meet the requirements of the project construction, and its quality should also meet the specified standards. If the inspection does not meet the standards, the machinery should be refused to enter the construction site .