An unexpected failure of the gear pump may cause significant effect on its performance and structure, consequently there will be economic losses. For this reason, fault diagnosis in meshed gears has been the subject of serious research. Vibration analysis is one of the pumps on condition monitoring techniques that determines a suitable maintenance action. Generally, an increased vibration level can be considered as a warning form before failure or breakdown. By measuring, processing, and analyzing the frequencies of vibration signal, it is possible to determine both the type and severity of the defect, and hence predict the machine's failure. The vibration signal of a gear pump contains the signature of the defects in the gears, and early fault detection of the gear pump is possible by analyzing the vibration signal using different signal processing techniques (Frequency Spectrum, Envelop and Power Spectrum Density). This research experimentally, shows the external gear pump signature for normal and faulty gear at different rotational speeds (1080, 1200 and 1439 RPM). The considered faults herein are one missing tooth and two missing teeth in a single gear of the pump. The Faulty gear signature due to missing one tooth and two missing teeth and at different rotational speeds are identified. The amplitude of vibration increases by increasing the rotational speed. When the two missing teeth are facing each other results in decreasing the vibration amplitude than one missing teeth size.

Gear pumps are critical devices in many industrial applications. An unexpected failure of the gear pump may cause significant effect on its performance. Consequently, there will be economic losses. As a result of that, fault diagnosis in gears has been the subject of intensive research. Vibration analysis has been used as an effective tool in machines diagnosis and in machinery maintenance decisions. As a rule, an increased vibration level is a warning form before failure or breakdown. By measuring and analyzing the gear pump vibration, it is possible to determine both the nature and severity of the defect, and hence predict the machine's failure. The vibration signal of a gear pump carries the signature of the fault in the gears, and early fault detection of the gear pump is possible by analyzing the vibration signal using different signal processing techniques. This paper presents, experimentally, the external gear pump signature for normal and faulty gear pumps at different rotational speeds (1080, 1200, and 1439rpm). The considered faults herein are two different notches on one of the pump teeth-small notch and large notch. The paper concludes that features of the vibration are different with the notch shape and the rotational speed. The amplitude of vibration increases by increasing both rotational speed and notch size.