5.1 Spur gear terms and concept Fig. 5.1 Terminology definitions for spur gears
The radial distance from the pitch circle to the outside diameter is called as addendum. The radial distance between the pitch circle and the root diameter is called as dedendum. The distance of the arc along the pitch circle from one side of a gear tooth to the other is called as circular thickness. The length of the arc of the pitch circle from one point on a tooth to the same point on the adjacent tooth is called as Pitch circle. Pitch diameter is nothing but the diameter of the pitch circle. The major diameter of the gear is called as outside diameter. Root diameter is defined as the diameter of the root circle measured from …show more content…
The gear vibration signals containing three subsets included the normal healthy condition as shown in figure 18, Gear teeth has been cut 4 mm depth from addendum circle that as shows in figure 19 and gear 2 teeth’s were defected as by it has cut 4 mm depth from addendum circle opposite sides each other that as shown in figure 20, are obtained from the experimental system under these three different conditions. The vibration signals are continuously acquired by an YMC145A100 IEPE accelerometer attached to the housing with magnetic bases and mounted at the top of the engine such that gear location nearer to the accelerometer. The advanced data acquisition and analysis system DP/INV306U with 10 kHz samples frequency is used to collect the vibration signal while the shaft’s rotating frequency is steady .An accelerometer is mounted on the flat surface of the engine such that it should be near to the engine gear using direct welding, adhesive mounting technique. The accelerometer is connected to the signal-conditioning unit (DACTRAN FFT analyzer), where the signal goes through the amplifier and an Analogue-to-Digital converter (ADC). The vibration signal in digital form is fed to the computer through an USB port. The software Pro-series that accompanies the signal-conditioning unit is used for recording the signals directly in the computer’s secondary memory. The signal is then read from the memory and replayed and processed to extract different features. . Since the mass of engine larger than the accelerometer the natural frequency of the accelerometer is very much higher than the engine natural frequency. The shaft of engine is supported at its ends by