Startup characteristics in hydraulic pump maintenance

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A few people who work on the repair of hydraulic pumps should be able to notice that, in the process of repairing such pumps, a starting characteristic of the hydraulic pump can be observed. What are startup characteristics? What are the requirements for the starting characteristics of a hydraulic pump when repairing it? Autos explains it to you in detail. In most mechanical devices, hydraulic pumps often start, stop, rotate in forward direction, and rotate in reverse direction under load. Under such conditions of frequent switching, the starting performance of the hydraulic pump must ensure reliable startup at any angular position, even when the load corresponds to the full torque or the allowable torque. Starting characteristics are measured by starting torque and starting mechanical efficiency. The torque on the output shaft of a hydraulic pump when it is started from a stationary state at its rated pressure is known as the starting torque of the hydraulic pump; in other words, it is the torque generated by the shaft after overcoming frictional losses during the startup process. After pressurized oil is supplied, the hydraulic pump must overcome static friction in order to start moving from a stationary state. That is, once pressure oil is supplied, the output shaft is rotated through a slight pre-tensioning angle in order to overcome the gaps between the moving parts as well as the elastic deformation of those parts. This puts the hydraulic pump in a pre-tensioned state prior to startup. At this point, Coulomb friction arises between the relatively sliding surfaces; as this friction increases, the output torque decreases. When the friction has reached a sufficient level, the output torque stabilizes at a certain value – this value is known as the starting torque. The hydraulic pressure enables the hydraulic pump to overcome this friction and thus start operating under load. Starting mechanical efficiency, also known as starting torque efficiency, refers to the ratio of the starting torque of a hydraulic pump when it is started from a stationary state to its theoretical torque. The magnitude of the starting torque and the starting mechanical efficiency of a hydraulic pump is affected by internal friction forces as well as torque pulsation. When starting with the output shaft in different positions (phase angles), the starting torque also varies slightly. In practical applications, it is desired to have better starting performance, that is, to achieve as high a starting torque and starting mechanical efficiency as possible. Hydraulic motors with different structural configurations have varying starting mechanical efficiencies (starting torque efficiencies). Hydraulic pumps with different structures have varying startup characteristics, and the key points to consider during their maintenance also differ. However, we can achieve the purpose of adjusting start characteristics by controlling the starting mechanical efficiency or starting torque. The starting characteristics in hydraulic pump maintenance are something that many people working on hydraulic pump repairs may not be aware of. However, Autos Hydraulic Repair Center, as a company with over a decade of experience in hydraulic repairs, has already taken these factors into account.