PSI - Issue 35

Gaston Haidak et al. / Procedia Structural Integrity 35 (2022) 124–131 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 4. Swashplate ’s stress, deformation and its related fatigue.

Fig. 5. Deformed slipper pad and its fatigue.

In Fig. 5, the deformation of the slipper border is observable; this agrees with the destruction of the ends, as we have seen in the spoiled machines. We can locate the places most exposed to damage and failure on the slipper pad (red colour area). The excessive fatigue on the slipper pad is caused not only by the load sustained by the slipper during regular pump operation but also by the swashplate’s reaction. The slipper pad undergoes a large area expo sed to damage and failure because of the friction force due to its applied load and the swashplate reaction force. The upper damage zone is due to the contact between the slipper pad and the retainer hole on the one hand and its connection with the piston head. It is worth noting that although the grounding in the axial piston machine affects almost all its components, the damage to the least voluminous components. The slipper is the most exposed when it comes to the damage analysis between the slipper and the swashplate. In general, the loss of performance in the axial piston machine most considered by researchers in the past was only the loss of performance due to fluid flow and friction forces. However, by limiting research on these two origin losses, the damage, loss of capacity due to deformation, and failure of the solid parts are not well considered. In addition, most of the machines undergoing sudden or rapid destruction always have fractured or even excessively deformed features. The repeated loading and unloading under the swashplate due to the non-uniform applied pressure forces can cause failure at the relatively small stresses. That phenomenon, a leading cause of failure, is what we are calling fatigue in our case. Its analytical solution is based on the nonlinear cumulative damage. For the validity of our results, the presented test rig in Fig. 3 is used for measurement. And by applying the 45-bar load on the slipper during the experiment, we were able to obtain the pressure of the slipper pocket and the time associated with it, as we can see in Fig. 6.