Fault origin of high-speed shaft of reducer of gan

2022-08-24
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cause analysis and improvement measures for the failure of the high-speed shaft of the reducer of the gantry crane crane running mechanism

the motor model of the gantry crane running mechanism is jzr242, the power is 16 kW, and the speed is 715 r/min; The reducer model is ZSC600 and the speed ratio is 3719 Through the stress analysis of the high-speed shaft of the reducer and the calculation of the strength, stiffness and fatigue of the shaft, it is considered that the strength, stiffness and fatigue of the shaft meet the requirements

212 cause analysis

since the strength, stiffness, fatigue, etc. of the shaft meet the requirements, it can be analyzed that the main reasons for the fracture of the high-speed shaft at section a - A are as follows:

(1) random error of the impact testing machine of the high-speed shaft: the load is large under the same conditions. Due to busy operation, frequent train braking, uneven track, transmission clearance and other factors, the impact load of high-speed shaft is large

(2) the fit of high-speed shaft key connection is too loose. High speed 24-hour door-to-door for you to deal with the problem. The width deviation of the shaft keyway adopts the general key connection N9; Due to the large impact load of the high-speed shaft, the keyway is plastically deformed, the keyway is widened, the key connection is loose, and the transmission clearance is increased; The increase of transmission clearance increases the impact load of the high-speed shaft, which further increases the plastic deformation of the keyway until the keyway is damaged or the shaft is broken

(3) stress concentration. At the a - a section of the high-speed shaft, the shaft diameter changes too much and there is no excessive fillet to cause stress concentration

3 improvement measures

in view of this, the following measures were taken when repairing the high-speed shaft:

responsible to the customer

(1) fillet transition was used at section A-A of the high-speed shaft to reduce stress concentration, and the fillet radius was 4 mm

(2) adjust the fit of high-speed shaft key connection. The width deviation of the keyway is changed from the general key connection N9 to the tighter key connection P9. At the same time, the keyway is quenched to ensure the transmission of torque at this place

(3) reconfigure the coupling so that its taper hole is consistent with the shaft taper, and the joint surface fits closely

(4) strengthen the inspection and maintenance of the crane running line to reduce the impact load during running

4 use effect

the high-speed shaft of the reducer broke down four times from 1993 to 1998. In 1998, the high-speed shaft of the reducer was improved according to the above improvement measures. So far, the high-speed shaft of the reducer of the crane running mechanism has not broken, and its keyway has not been damaged

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