Failure analysis of excavator hydraulic pump

Hydraulic pump failures may be related to hardware or problem in oil. In this study, the excavator hydraulic pump failures were investigated by using visual observed and measuring the part component. The disassembled process of the pump was performed considering the manual part book of the excavator hydraulic pump. The abrasive wear on the pump slipper and swash plate was observed by comparing the guidelines for the reusable part. The value of more than 1.07 mm clearance within piston and cylinder bore was measured then the results over the allowable limit considering the manual part book. Properly analyzing of component failure can provide valuable information about what caused the failure and thus can be to avoiding future unscheduled downtime.

Multi-input Convolutional Neural Network Fault Diagnosis Algorithm Based on the Hydraulic Pump

Convolutional neural network used in fault diagnosis can effectively extract fault features in vibration signals. However, in the feature extraction of mechanical fault diagnosis, usually more than two feature signals including at least axial and radial vibration signals can be extracted. This paper proposes two multi-input convolutional neural network models based on the fault data of the aircraft hydraulic pump including axial and radial vibration. The first is the Independent Input Multi-input Convolutional Neural Network model. The two inputs are respectively used for convolution pooling operation with CNN, and are combined through the concatenate function before the fully connected layer, and then all frames are integrated and flattened by the flatten function. A one-dimensional array, finally enters the fully connected layer and outputs the result through the softmax function. The second is the Combined Input Multiinput Convolutional Neural Network, that is, combine two one-dimensional signals into a twodimensional signal in the input layer of the convolutional neural network and then perform convolution pooling, and finally output the result through the softmax function. The results show that the two models have good accuracy and stability, and the second one has a higher convergence and fitting efficiency than the first one.

Research on Control Method of the Power System of Stepping-Type Anchoring Equipment

To improve the roadway adaptability and control accuracy of anchoring equipment, a stepping anchoring device was designed. A permanent-magnet synchronous motor control and a harmonic suppression algorithm were integrated to optimize the dynamic control system of stepping-type anchoring equipment. The results of an experimental simulation and analysis showed that when the coefficient of coal rock hardness f = 5, 6, and 7, the pulsation coefficient of the hydraulic pump outlet pressure, hydraulic motor output speed, and pump-controlled hydraulic cylinder advance speed in the hydraulic circuit of a pump-controlled motor did not exceed 3% after the equipment based on sliding mode control (SMC) entered the steady state, while the maximum pulsation coefficient was only 32.5% of the PI control. Based on the SMC, the harmonic components of the permanent magnet synchronous motor in the power system were suppressed and compensated for. This enhanced the stiffness of the hydraulic system under motor drive. When the rock stiffness factor gradually changed from f = 5 to f = 8 and increased suddenly from f = 5 to f = 6, the pressure overshoot at the outlet of the hydraulic pump of the pump-controlled motor system was reduced from 11.19% to 7.97% and from 61.19% to 52.88%, respectively, compared with that before the optimization. It was thereby proven that SMC based on harmonic suppression can effectively reduce the system pulsation caused by the multi-factor coupling of anchoring equipment and provide technical support for the optimal control of the power system of stepping-type anchoring equipment.

The RAMPDOOR HYDRAULIC SYSTEM MODIFICATION OF ANOA PANZER COMBAT VEHICLE

Panzer Anoa 6x6 is a combat vehicle on tires where the first generation of it is made by PT Pindad (Persero). It can mobility, protection and carrying capacity. The ramp door on the Anoa 6x6 APC armored vehicle is driven by a hydraulic system to support the mobility of personnel when exiting or entering the vehicle. The components of the hydraulic system driving the Panzer Anoa 6x6 APC ram door include batteries, power packs, solenoid valves, hydraulic hoses, and hydraulic cylinders. These problems include the ramp door often not functioning, the ramp door moving too slowly and often experiencing congestion when the ramp door is working. These constraints often occur because the pump in the hydraulic system is driven by an electric motor that gets its power source from the battery. The fluid is pressed and flowed through a hydraulic pipe, then the flow of the pressurized fluid is regulated by a solenoid valve to the hydraulic cylinder to move the ramp door. This study uses a pure experimental quantitative method with empirical calculations to obtain a tool with the desired specifications. To move the ramp door weighing 200 kg with a maximum opening angle of 100 degrees in 8 seconds, the heaviest load received by the cylinder is 23557.44 N, the working pressure that occurs in the cylinder is 87.49 bar, where the fluid discharge will flow to the pump. of 2164.77 liters/minute, with a pump power of 394570 Watt and to continue the rotation of the engine with a rotation of 2814.13 rpm (idle) to the hydraulic pump using a pulley mechanism with a ratio of 1: 0.15.

Dynamic Modeling and Design of a Radial Hydrostatic Piston Pump for Integrated Pump-Motor

There is a current trend towards the electrification of high force/torque density machines that have traditionally been dominated by diesel engine driven hydraulics. Power dense electric machines tend to favor high operating speeds whereas a hydraulic pump is more efficient at low speed and high torque conditions. The power density of a pump can be increased by decreasing the displacement and increasing the operating speed to provide the flow demand. This miniaturization of the pump allows it to be directly integrated into an electric motor inside a single casing. This integrated pump-motor is free of shaft seals and eliminates a set of bearings otherwise required when coupling an electric motor and pump with a shaft. Additionally, the leakage from the hydraulic pump can be used as coolant for the electrical machine, thereby improving the power density. In this paper, a hydrostatic radial piston pump has been evaluated for integration with an axial flux PM machine. The proposed hydrostatic piston pump uses a spherical head piston that can tilt while reciprocating inside the cylinder, eliminating the need for a joint at the slipper. To reduce the frictional loss between the slipper pad and the cam at high operating speeds, the cam freely rotates. A detailed model of the pump, with focus on the hydrostatic piston slipper, has been developed and a grid search approach has been utilized to select the critical parameters of the pump. Finally, an efficiency map has been presented for this pump at different operating conditions which shows around 86% efficiency at the 12500 rpm speed for 7 MPa pressure differentials.

Simulation and Experimental Analysis of Pressure Pulsation Characteristics of Pump Source Fluid

The output flow pulsation characteristics of the hydraulic pump due to the structural characteristics may cause pump source fluid pressure pulsation and even cause the equipment to vibrate, which will affect the life and working reliability of the equipment. Scholars have done a lot of theoretical and simulation analysis on the characteristics of fluid flow and pressure pulsation caused by the specific structure and structure of the plunger pump, but there are few comparisons and analyses of the simplified model of the plunger pump and the pressure pulsation characteristics with experiments. In this paper, AMESim software is utilized to establish a simplified model of one seven-plunger hydraulic pump, and simulate and analyze the pump source fluid pressure pulsation characteristics of different system load pressures at a constant speed. An experimental platform for testing pump fluid pressure pulsation was designed and built, and the actual measurement and simulation results of pump fluid pressure pulsation were compared and analyzed. The results show that the system simulation data is in good agreement with the measured data, which verifies the correctness of the simplified model of the plunger pump. At the same time, it is found that the fluid pressure pulsation of the pump source exhibits broadband and multi-harmonic characteristics. At a constant speed, as the load pressure of the hydraulic system increases, the pump source fluid pressure pulsation amplitude increases, the pressure pulsation rate decreases, and the impact on the fundamental frequency amplitude is the most significant. The research results can provide a theoretical basis for suppressing the pressure pulsation of the pump source fluid and reducing the vibration response of a hydraulic pipeline under the action of the pulsating harmonic excitation.