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Offshore Drilling
Published in Sukumar Laik, Offshore Petroleum Drilling and Production, 2018
The rotary table (Figure 4.12) itself is a very simple design and has changed little over the years. The rotating table is usually cast of alloy steel and fitted underneath with a ring gear which is shrunk onto the table proper. The table is supported either by ball or tapered roller bearings capable of supporting the dead load of the string of the drill pipe or casing which may be run into the well. Provisions in the form of suitable bearings must also be made for holding the table in place against any possible tendency to upward movement imparted during rig operations. Suitable guards are arranged so that mud or water cannot get into the oil bath provided for the gears and bearings. The ring gear and its driving pinion gear are customarily of spiral bevel construction, which provides for smoother operation than straight bevel gears. The speed reduction from the pinion shaft to the table is of the order of 3 or 4 to 1. The pinion shaft is customarily furnished with antifriction bearings, often of tapered roller design. It is also equipped with oil seals and guards to prevent entry of mud or water into the interior of the equipment.
Lubrication and Wear Analysis of Planetary Roller Screw Mechanism With Threaded Surface Roughness in Thermal Elastohydrodynamic Lubrication
Published in Tribology Transactions, 2022
Jiacheng Miao, Xing Du, Chaoyang Li, Xinping Shan, Bingkui Chen
The following heat sources, that is, thermal elevation factors in the model, are considered:Frictional heat of bearings ( for the support bearing).Frictional heat caused by thread meshing ( for the roller–screw interface and for the nut–roller interface).Frictional heat between roller gear and ring gear ().Frictional heat between roller, nut, and carrier ( for the roller and for the nut).
Current State of the Design Engineering of the Versatile Test Reactor Plant
Published in Nuclear Science and Engineering, 2022
Steven Unikewicz, Eric Loewen, George Malone
For refueling operations, the primary seal is deflated (to prevent rolling the seal), and sealing is provided instead by a gas-buffered dynamic seal. Unlike the primary seal, the dynamic seal is designed to accommodate the sliding action that occurs during RP rotation. It consists of a pair of inflatable elastomeric seal rings that act against a pair of blade-like steel runners. The dynamic seal is leak checked by monitoring the annulus between the two seal rings. The RP static and dynamic seals and bellows are designed to meet the gas leakage criteria for normal reactor operation. During preparation for refueling, multiple evolutions are carried out to prepare the RP. The control rod and safety rod drivelines are decoupled from the absorber assemblies which remain in the core. The control rod and safety rod drivelines are then withdrawn such that the RP can rotate freely. The RP holddown bolts are loosened. The dynamic seals are inflated, and the primary seals are deflated. The RP is raised off the ledge seal with three jackscrew assemblies. This arrangement provides precise and repeatable alignment while maintaining clearance at the ledge seal. The RP rotation is initiated by a gear motor, mounted on the drive bearing outer race, which engages a pinion gear. The pinion gear drives the ring gear, and thus, the RP.
Final detailed design of an all-in-one attachment-based PHC pile head cutting robot and its structural stability analysis
Published in Journal of Asian Architecture and Building Engineering, 2021
Ji-Young Hwang, Dong-Jun Yeom, Jun-Sang Kim, Young Suk Kim
The diamond wheel saw-based detailed design was designed to operate based on the movement of the driving frame along the driving rail meshed with the main roller, in conjunction with the concurrent operations of seven driving rollers and the concurrent rotation of the timing belt. The driving frame was positioned on the base plate of the cutting base frame, and was connected to the main roller among the driving rail in a serrated manner. In addition, the diamond wheel saw connected to the ring gear was designed to operate stably by the rotation of the maintenance roller and the swing belt so that the pinion roller connected to the maintenance roller rotated and the ring gear meshed with the pinion roller rotated along the guide roller (Figure 9).