Improvement Plan for the Balance of the Lever Swing in Tensile Testing Machine
Starting from the first thermal performance test device for suspension insulators in China, each improvement of domestic tensile testing machines has filled the gaps in the field of tensile machines and material testing machines in our country. These improvements have established necessary testing methods for the export of our products and laid a good foundation for further research on the performance of suspension insulators.
1.Reduce the motor speed in the speed control motor: thereby narrowing its lower limit range, in order to achieve the goal of lowering the minimum speed of the C-axis.
2. By increasing the reduction ratio of the planetary gear pinwheel reducer (referred to as the reducer), the minimum speed of the C-axis can also be reduced.
According to our investigation, the minimum rotational speed of the motor is 960 r/min, while the original rotational speed of the testing machine's motor is 1200 r/min. If we replace the motor with one that rotates at 960 r/min, the rotational speed per minute will only decrease by 240 r, which is not significant and does not meet the requirements. Therefore, this method is not suitable. Thus, we should consider changing the reducer instead. When replacing the reducer, we take into account the power matching of the replaced reducer and the need to have a larger reduction ratio. We also consider the issue of interchangeability. At the same time, we have conducted relevant strength calculations and verification tests, and thus concluded that increasing the reduction ratio of the reducer and reducing the rotational speed of the output shaft will not damage the A shaft, the sleeve B and the pump C. According to the relevant manual, the XW1.5--53-289 (187) type reducer is similar in installation size and power to the reducer before replacement, and its reduction ratio has increased by 3 to 5 times, which is quite suitable. Therefore, we decided to use the XW1.5--53-289 type reducer. Since the power of the reducers before and after replacement is the same and their installation sizes are basically similar, their interchangeability is good, which greatly reduces the workload and engineering costs, and ensures the accuracy of the tensile testing machine.
After the reducer was replaced, the balance problem of the lever swing of the tensile machine was resolved. The tensile load was below 58kN (6t), and the lever would automatically balance after two up-and-down swings. This basically met the operational requirements. The performance comparison of the tensile machine before and after the reducer replacement is listed in the following table.
After the improvement of the lever swing balance in the thermal machine device, it has made the operation of the test personnel more convenient and enhanced the accuracy of the thermal machine performance test for suspension insulators.
