Development of an In-Pipe Robot With Differential Screw Angles for Curved Pipes and Vertical Straight Pipes

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Te Li ◽  
Shugen Ma ◽  
Bin Li ◽  
Minghui Wang ◽  
Zhiqiang Li ◽  
...  

The in-pipe robots based on screw drive mechanism are very promising in the aspects of pipe inspecting and maintaining. The novel design of an in-pipe robot with differential screw angles is presented for the curved pipes and vertical straight pipes. The robot is mainly composed of the screw drive mechanism, adaptive linkage mechanism, and the elastic arm mechanism. The alternative adjusting abilities of the mobile velocity and traction, and the adaptive steering ability in curved pipes, are achieved by the special designs. A parameter design approach in consideration of the climbing and steering abilities is proposed in detail for the springs and length of the elastic arms. The results are applied to the prototype design of the robot. In several groups of experiments, the proposed robot is competent to pass through curved pipes and vertical straight pipes. The results prove that the proposed mechanism and parameter design approach are both valid.

2020 ◽  
Author(s):  
Prakash Subramaniam ◽  
S. Sundaram ◽  
K. Gunasekaran ◽  
G. Vikas Reddy ◽  
Kaja Bantha Navas Raja Mohamed ◽  
...  
Keyword(s):  

2018 ◽  
Vol 118 ◽  
pp. 191-199 ◽  
Author(s):  
Basel Arafat ◽  
Magdalena Wojsz ◽  
Abdullah Isreb ◽  
Robert T. Forbes ◽  
Mohammad Isreb ◽  
...  

1997 ◽  
Vol 119 (1) ◽  
pp. 57-63 ◽  
Author(s):  
M. J. Goodwin ◽  
P. J. Ogrodnik ◽  
M. P. Roach ◽  
Y. Fang

This paper describes a combined theoretical and experimental investigation of the eight oil film stiffness and damping coefficients for a novel low impedance hydrodynamic bearing. The novel design incorporates a recess in the bearing surface which is connected to a standard commercial gas bag accumulator; this arrangement reduces the oil film dynamic stiffness and leads to improved machine response and stability. A finite difference method was used to solve Reynolds equation and yield the pressure distribution in the bearing oil film. Integration of the pressure profile then enabled the fluid film forces to be evaluated. A perturbation technique was used to determine the dynamic pressure components, and hence to determine the eight oil film stiffness and damping coefficients. Experimental data was obtained from a laboratory test rig in which a test bearing, floating on a rotating shaft, was excited by a multi-frequency force signal. Measurements of the resulting relative movement between bearing and journal enabled the oil film coefficients to be measured. The results of the work show good agreement between theoretical and experimental data, and indicate that the oil film impedance of the novel design is considerably lower than that of a conventional bearing.


2018 ◽  
Vol 185 ◽  
pp. 00018
Author(s):  
Albert Wen-Jeng Hsue ◽  
Yi-Zhong Zheng

Tungsten carbide is a typical difficult-to-cut material by conventional machining processes. In this paper, a novel design of flexible abrasives tool combined with a rotary ultrasonic machining (RUM) spindle is conducted to reduce the labor force significantly. The newly designed flexibility of tool-tip is aimed at preventing overcutting from the CNC grinding. The grinding conditions with resulted surface morphology of the tungsten steel were investigated through Taguchi design of experiment and ANOVA analysis. The machining capability of the novel flexible tool is compared with conventional tools through specific grinding paths under proper operational conditions.


2018 ◽  
Vol 76 (5) ◽  
pp. 515-537 ◽  
Author(s):  
Neeraj Bhandari ◽  
Dennis P. Scanlon ◽  
Yunfeng Shi ◽  
Rachel A. Smith

Despite growing investment in producing and releasing comparative provider quality information (CQI), consumer use of CQI has remained poor. We offer a framework to interpret and synthesize the existing literature’s diverse approaches to explaining the CQI’s low appeal for consumers. Our framework cautions CQI stakeholders against forming unrealistic expectations of pervasive consumer use and suggests that they focus their efforts more narrowly on consumers who may find CQI more salient for choosing providers. We review the consumer impact of stakeholder efforts to apply the burgeoning knowledge of consumers’ cognitive limitations to the design and dissemination of the new generation of report cards; we conclude that while it is too limited to draw firm conclusions, early evidence suggests consumers are responding to the novel design and dissemination strategies. We find that consumers continue to have difficulty accessing reliable report cards, while the media remains underused in the dissemination of report cards.


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