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Lubricating Bearings and Other Machine Elements
Published in Heinz P. Bloch, Kenneth E. Bannister, Practical Lubrication for Industrial Facilities, 2020
Heinz P. Bloch, Kenneth E. Bannister
With oil bath lubrication it is generally sufficient to change the oil once a year, provided the operating temperature does not exceed 50°C and there is little risk of contamination. Higher temperatures call for more frequent oil changes, e.g., for operating temperatures around 100°C, the oil should be changed every three months. Frequent oil changes are also needed if other operating conditions are arduous.
Bearings and Lubrication
Published in Ansel C. Ugural, Youngjin Chung, Errol A. Ugural, MECHANICAL DESIGN of Machine Components, 2018
Ansel C. Ugural, Youngjin Chung, Errol A. Ugural
The splash system of lubrication is used effectively when a machine has a rotating part, such as crank or gear enclosed in a housing. The moving part runs through a reservoir of oil in the enclosed casing. This causes a spray of oil to soak the casing, lubricating the bearing. The term oil bath refers to a system where oil is supplied by partially submerging the journal into the oil reservoir, as in the railroad partial bearings.
Transmission
Published in Andrew Livesey, Advanced Motorsport Engineering, 2012
For some applications multi-plate clutches are run in an oil bath – referred to as wet. The oil bath acts as a lubricant, maintaining an even coefficient of friction between the plates to give smooth operation, taking away dust particles and acting as a coolant. On carbon clutches running them wet actually increases the coefficient of friction.
Two-step simulation of piezoelectric properties of porous PZT according to porosity
Published in Journal of Asian Ceramic Societies, 2023
Il-Gok Hong, Ho-Yong Shin, Jong-Ho Kim, Un-Gyu Paik, Jong-in Im
For the experimental verification of property optimization, porous PZT was synthesized using calcined KICET PZT-8 powder via a conventional solid-state reaction process. Polyvinyl alcohol (PVA) was added to the dried powders at 4 wt%, and spherical poly methyl methacrylate (PMMA) powder with an average particle size of 35 μm was added at ~10–50 vol%. The powders were molded into shapes according to the IEEE standards [24]. Each shape was divided into radial (RAD), thickness expansion (TE), transverse shear (TS), and longitudinal expansion (LE) modes according to the vibration mode. The molded samples were sintered at 1250°C for 2 h in a sealed alumina crucible containing atmospheric powder with the same composition as the specimens. The specimens were poled in a silicone oil bath at 120°C under an applied electric field of 2.5 kV/mm for 30 min. The piezoelectric properties were calculated by measuring the impedance characteristics using an impedance analyzer (HP 4194A, Agilent).
Dependence of local atomic structure on piezoelectric properties of PbZr1−xTixO3 materials
Published in Journal of Asian Ceramic Societies, 2022
Il-Gok Hong, Jong-Ho Kim, Ho-Yong Shin, Chan-Yeup Chung, Un-Gyu Paik, Jong-in Im
For experimental validation of DFPT calculation, the specimens were synthesized using a conventional solid-state reaction process. The composition of PZT and PSZT are given as follows: (PZT), (PSZT). The raw materials such as PbO, ZrO2, TiO2, and SrO for the given composition were weighted by the molar ratio, and the powders were ball milled. And the mixed powders were calcined at 900°C for 3 h and sintered at 1300°C for 3 h in a sealed alumina crucible containing atmosphere powder, which has the same composition with specimens. The specimens were poled in a silicone oil bath at 120°C by applying an electric field of 2kV/mm for 30 min. The piezoelectric charge constant (e33) was determined according to the method of resonance and antiresonance frequencies by using an impedance analyzer (HP 4194A, Agilent) based on the Institute of Electrical and Electronics Engineers (IEEE) standards [21], and the piezoelectric charge constant (d33) was measured using d33-meter (PM-300, Piezotest).
Effects of quenching on bending strength and piezoelectric properties of (Bi0.5Na0.5)TiO3 ceramics
Published in Journal of Asian Ceramic Societies, 2020
Yuka Takagi, Hajime Nagata, Tadashi Takenaka
The densities of the ceramics were measured by the Archimedes method. The ceramics were processed for various physical and electrical measurements. The crystal structure and lattice constant were observed by X-ray diffraction using Cu Kα radiation (XRD: Rigaku RINT-2000, 40 kV, 40 mA) on the surface of each bulk specimen. Gold electrodes were fabricated on each ceramic by sputtering for the measurement of dielectric and piezoelectric properties. The longitudinal vibration in the (33) mode was measured using a rectangular solid specimen of 2 × 2 × 5 mm3. The samples for piezoelectric measurement were poled in a silicone oil bath by applying a dc electric field of 5 kV/mm for 5 min at RT. The piezoelectric properties were evaluated by the resonance – antiresonance method in accordance with IEEE standards using an impedance analyzer (HP4294A). The temperature dependences of the same setup of the impedance analyzer were evaluated from RT to about 350°C. Then, the depolarization temperature Td was determined from the temperature dependences of the dielectric constant εr and loss tangent tanδ.