This paper proposes a piezohydraulic hybrid actuator driven by a resonant vibrator based on two rhombic micro-displacement amplifiers. The resonant piezohydraulic hybrid actuator consists of a resonant piezoelectric vibrator, a pump body, a manifold, a return valve, and an output cylinder. The vibration mode of the piezoelectric vibrator is simulated, and the working principle of the resonant piezohydraulic hybrid actuator is depicted. Then, the performance of the piezohydraulic hybrid actuator is experimentally investigated, and the effects of exciting frequency, exciting voltage, and bias pressure are analyzed. The results demonstrate that the hybrid actuator performs the best when the exciting frequency is near the resonant frequency; meanwhile, the higher the exciting voltage, the better the performance. Moreover, it indicates that a larger bias pressure will bring a larger reaction force to the vibrator and reduce the performance of the actuator system. The maximum blocked force and no-load velocity are 378 N and 4.8 mm/s, respectively, when the bias pressure is 1.5 MPa and the exciting voltage is 500 Vpp.

This study describes the remanufacturing process scheme and key technologies of waste compressors. Firstly, the technical characteristics of compressors for home appliances such as refrigerators and air conditioners are summarised. Then, the remanufacturing process scheme is proposed with the waste refrigerator compressor as the research object. The purpose or requirements of key processes such as separation, disassembling, cleaning, detecting, remanufacturing and reassembling are also elaborated. Moreover, the corresponding remanufacturing technology or method is proposed to satisfy the structural, quality requirement, economy and environmental friendliness of products and components. The cleaning technology of the compressor motor stator and the remanufacturing technology of crankshaft is highlighted. In accordance with the structural and quality requirement of the motor stator, the cleaning method of the motor stator is proposed, and the environmental friendliness, economy and safety of several cleaning agents are analysed. The scheme of crankshaft remanufacturing is proposed on the basis of the failure form of the crankshaft and the quality requirement of remanufacturing. Moreover, the process parameters are described.

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This paper introduces the design, manufacture, dynamic analysis, and experimental results of a piezoelectric pump driven by the inertial force of a vibrator supported by a slotted beam. The piezoelectric vibrator is composed of a mass block, displacement amplifier, and slotted beam fixed with both ends. In the resonant mode, the displacement amplifier drives the slotted beam to work, and produces amplitude and inertial force. In this paper, the design of the slotted beam optimizes the output of the displacement amplifier. In addition, the slotted beam supports the displacement amplifier and increases the elastic output. The pump body adopts polydimethylsiloxane (PDMS) check valves and compressible spaces to improve the output performance. This research studies the influence of stiffness and mass on the output performance by qualitatively analyzing the inertial output force of the vibrator. Nine kinds of slotted beams with different stiffnesses and different mass blocks are designed for comparison. Thereafter, an optimal structure of the piezoelectric pump is selected. The experimental results show that under a driving voltage of 700 Vpp , the maximum flowrate is 441 mL min−1 and the maximum back pressure is 25.3 kPa.