A gear box exported by our company, technical requirements: test noise under the condition of input speed 540r/min, output speed 794r/min, output 3k W, and must not exceed the specified value. At the beginning, we used the mechanical and electromagnetic brakes on the output to load the output. The effect is not good. First, because the gearbox is increasing speed, the output speed is higher. When used, the friction heat is large, and the specific loading value cannot be determined, and the measured result is not accurate. Later, we switched to the output of the magnetic powder brake, the effect is very good, the operation is convenient and the measured value is accurate. The magnetic powder brake is based on the electromagnetic principle and uses the magnetic powder to transmit torque. It has a linear relationship between the excitation current and the transmission torque. It can transmit a certain torque regardless of the slip, and has a fast response speed and a simple structure. It is a multi-purpose, superior performance automatic control component, widely used in various machinery for different purposes of braking, loading and so on. The specific structure of the noise measuring device is shown in Figure 1: figure 1 1. Transmission shaft 2. Transmission belt 3. Pulley 4. Workbench welding 5. Inlet pipe (return pipe) 6. Inlet pipe (connected to cooling pump) 7. Wire 8. Magnetic powder brake 9. Spline sleeve welding 10. Current meter 11. Motor 12. Spline shaft welding 13. Fixing plate 14. Measured gear box 15. Universal joint The loading value of the magnetic powder brake is controlled by current, first according to the formula: N=Mn/9549.29 In the middle N——slip power, kW M——torque, N·m n - speed, r / min Calculate the torque M value, ie M=9549.29N/n=9549.29×3/794=36.08(N·m) Then, the current value (the excitation current of the device is 0.28A) can be detected by the excitation current-torque characteristic diagram (see Fig. 2) in the factory test report of the magnetic powder brake. Next page Snap off Blade Utility Knife,Abs Snap off Blade Utility Knife,Snap-Off Blade Cutter Knife Shangqiu Acer Measuring Tool Co.,Ltd. , https://www.acertoolshn.com