Crane accessories wheel set is a product that must be prepared for lifting equipment. Since cranes use many accessories, different accessories for wheel sets are very important for crane maintenance.
The horizontal deflection value of the crane operating mechanism is an important technical parameter of the crane, the deviation value will cause rail gnawing, increase the running resistance resistance, vibration and noise, increase the track and wheel wear, greatly reduce the service life of the crane, so all kinds of crane manufacturing technical conditions to the wheel horizontal deflection of the allowable value.
Problems and maintenance methods of crane wheel forging
1. Wheel tread wear: wheel tread wear more than 15% of the original thickness should be replaced with new parts, do not exceed this value, can be re-turned, heat treatment repair. The diameter of the wheel should be within the tolerance range, the surface quenching hardness HB300-500, the thickness of the quenching layer of the wheel diameter greater than 400㎜ should be greater than 20㎜; When the diameter is less than 400㎜, the quenching thickness should not be less than 15㎜;
2. Diameter deviation of two matching wheels: the diameter deviation of the active wheel should not exceed 0.1% of the nominal diameter, the driven wheel should not exceed 0.2%, the diameter deviation of the electric hoist wheel should not exceed 1% of the nominal diameter, and the driven wheel should not exceed 0.2%; Wheel diameter deviation of electric hoist should not exceed 1% of nominal diameter;
3. Rim wear and break, deformation: rim wear up to 50% of the original thickness or broken area more than 30mm2 should be scrapped, rim thickness bending deformation up to 20% of the original thickness should be scrapped;
4. Wheel cracks: crane wheels found cracks should be scrapped;
5. Tread ellipticity: the tread ellipticity of the crane wheel reaches 1㎜ should be scrapped
6. Wheel group assembly: The installed wheel assembly should be able to rotate flexibly, and several wheels installed on the unified balance frame are in the same vertical plane, allowing a deviation of 1㎜.
In application, the control of wheel horizontal deflection value of running mechanism is mainly based on different product structure to take corresponding technical measures. The design structure that is more commonly used and the process measures are relatively simple is: the wheel is assembled on the bracket to form a wheel group, such as the angular bearing box wheel group and the trolley type 45° split bearing box wheel group, and the horizontal deflection of the wheel is installed and adjusted on the main structure of the crane.
When the crane fails, the first time to check the cause of the wheel group, if the whole part can not work due to various reasons, the wheel group needs to be replaced, replaced, or the correct replacement, which will lead to the lifting equipment can not work, or the working performance is reduced. The construction environment of the wheel group is usually harsh, and the probability of equipment problems is relatively large, and the wheel group needs to be avoided as far as possible. The maintenance of the wheel group of lifting accessories is very important, which is not only related to the performance and loss of the wheel group, but also the guarantee of normal operation.
Wheel group in the lifting industry application process from a professional point of view, the role of maintenance is even heavier than replacement, the wheel group in the construction of the accessories has reached a running-in process, then we as long as the maintenance work can make the equipment performance more stable, the wheel group after the replacement of accessories and new running-in, which greatly affects the performance of the wheel group equipment.
When the wheel group is overhauled, the axle holes of the wheel group need to be checked regularly, and the defects and depth of the axle holes are strictly regulated. If you exceed the limit, you need to replace the parts. If the radial wear of the pulley groove of the wheel set exceeds 32% of the wall thickness, replace it with a new one. There is no more than the in-service maintenance, the maintenance interval can not exceed 0.5 mm. When the pulley of the wheel group is repaired, it is necessary to check whether there is a crack, and the wear of the journal of the component can not exceed 40%, otherwise replace the new part. The wheel group of the crane parts needs to be disassembled during the overhaul, and the wheel group should be assembled in time after the inspection and maintenance. Testing is required after assembly.