LUBRICATION FILM FORMATION MECHANISM OF SLIPPER PAIRS IN LOW SPEED HIGH TORQUE HYDRAULIC MOTORS

Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connecting rod type low speed high torque （LSHT） hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerically studied by computer simulation. Effects of supply pressure, initial lubrication film thickness, velocity damping coefficient, loading impact and gravity, etc are studied. Advantages of novel slipper pairs with large oil cavity area are pointed out.

Interfacial phase formation of Al-Cu bimetal by solid-liquid casting method

The solid-liquid method was used to prepare the continuous casting of copper cladding aluminium by liquid aluminum alloy and solid copper, and the interfacial phase formation of Al-Cu bimetal at different pouring temperatures(700, 750, 800 oC) was investigated by means of metallograph, scanning electron microscopy(SEM) and energy dispersive spectrometry(EDS) methods. The results showed that the pouring temperature of aluminum melt had an important influence on the element diffusion of Cu from the solid Cu to Al alloy melt and the reactions between Al and Cu, as well as the morphology of the Al-Cu interface. When the pouring temperature was 800 oC, there were abundant Al-Cu intermetallic compounds(IMCs) near the interface. However, a lower pouring temperature(700 oC) resulted in the formation of cavities which was detrimental to the bonding and mechanical properties. Under the conditions in this study, the good metallurgical bonding of Al-Cu was achieved at a pouring temperature of 750 oC.

Ionic Polymer-Metal Composite Electro-Active Nano-biopolymer Actuator

This research article introduces an electroactive actuator based on sulfonated chitosan(SCS),ionic liquid and graphene oxide(GO).To maintain the biocompatibility of the chitosan and to increase the actuation performance,a biocompatible ionic liquid such as ethyl,methylimidazolium-trifluoro methane sulfonated(EMI-TFMS)as mobile solvent was used for dry-type actuation.And GO-reinforced SCS films obtained through a simple solvent casting method were extensively investigated because of better electro-chemo-mechanical properties and higher actuation performances.Field-emission scanning electron microscope(FE-SEM),X-ray diffraction(XRD),Fourier transformer infrared spectroscopy(FT-IR),and Raman spectra were used to investigate the interaction mechanism between GO and SCS.The harmonic and step responses of GO and SCS composite actuator show large bending deformations under low electric voltage.

Sand-polished Kapton film and aluminum as source of electron transfer triboelectric nanogenerator through vertical contact separation mode

Contact electrification is a direct triboelectrification method for producing current through charge transfer when two different differentiated materials have brought into contact.For the first time,we developed a simple triboelectric nanogenerator(TENG)where the electronic charges were realized through contact separation mode between sand-polished Kapton(SPK)and Al surface.Here,we demonstrated the energetic interfacial contact between these surfaces and observed satisfactory output performance.The novel SPK-TENG produced 40 V and 2.8μA,of open-circuit voltages(V_(oc))and short-circuit currents(Isc)at 4 Hz,respectively.Mainly,the SPK-TENG was dramatically increased up the performance of TENG,up to 40% of V_(oc) and 42% of I_(sc),with respect to the Kapton film because the mobility of electrons is very high on the device surface compared to the other pristine Kapton film.The fabricated SPK-TENGs were good candidates for satisfying the need for alternative contact separation mode TENGs.