Research on the rotational inertia of radial piston pump and the optimization method of the pump parameters
This paper aims to propose a method of optimizing the structure of radial piston pump from the aspect of reducing the rotational inertia. A modeling method based on basic dimensions and scale factors is developed. By using this method, three different types of radial piston pumps are studied. And the relative rotational inertia coefficient is adopted to evaluate the difference among them. Further study states that the relative rotational inertia coefficient changes along with the eccentricity ratio and the thickening factor. Finally a criterion is obtained, which could be used to optimize the structure and the dimensions of radial piston pumps.
Design and experimental studies of a novel double-row radial piston pump
This paper proposed a novel double-row radial piston pump. In this pump, the transformation from the rotation of the shaft to the reciprocation of the piston is realized by a pentagon mechanism, and the oil is distributed by check valves, which are integrally designed on the pump body. Theoretical calculation demonstrated that this improved design can substantially reduce the force on the main shaft of pump. The formulas of instantaneous flow rate and fluctuation coefficient of the pump are deduced. For studying the working characteristics of the pump further, a prototype was manufactured and tested. Results show that when the rotation speed is over 125 r/min, the performances of pump prototype are qualified, the fluctuation rate is limited to 20% and the volumetric efficiency can reach 90%. Moreover, the pump was disassembled after 100 h of service and the wear condition was checked. Except for the pentagon which has indentation on the surface, the components of the pump are all kept intact.
Accountability perception of Thai Government: to whom and what counts
PurposePublic sector entities face conflicting demands from stakeholders. The literature suggests identifying and prioritizing stakeholders can improve accountability. Thailand, an emerging economy, and currently under military rule, provides an interesting context to investigate stakeholder tensions. The purpose of this paper is to investigate how and why the Thai Government bureaucrats prioritize their stakeholders.Design/methodology/approachThe study draws on the managerial branch of stakeholder theory and stakeholder salience theory to examine the importance of various stakeholders and of the stakeholders’ salient attributes perceived by the Thai Government bureaucrats in discharging its accountability. The study uses a survey questionnaire mailed out to the central government departments in Thailand.FindingsThe study finds that single most important stakeholder is the Office of the Auditor-General. The public is perceived as the second. This is dissimilar to the western-centric accountability focus on the public, and challenges claims by the Thai military coup that it will bring democratic rule. “Legal power” supporting the stakeholders’ claims for government accountability is the most influential attribute in determining stakeholder importance and prioritizing attention for government bureaucrat’s discharge of its accountability.Originality/valueSuch findings increase understanding of the applicability of stakeholder theory and stakeholder salience theory in the context of military rule in emerging economy countries such as Thailand. This paper also provides suggestions of how stakeholders may shape their salience in order to gain priority. This also provides an immediate suggestion for reforms of the Thai regulatory frameworks in prioritizing stakeholders and promoting the government’s greater accountability.