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Internally geared screw machines with ported end plates

Read, M. G., Smith, I. K. & Stosic, N. (2017). Internally geared screw machines with ported end plates. IOP Conference Series: Materials Science and Engineering, 232(1), article number 012058. doi: 10.1088/1757-899x/232/1/012058


It is possible to design cylindrical helical gearing profiles such that an externally lobed inner gear rotates inside an internally lobed outer gear while maintaining continuous lines of contact between the gears. The continuous contact between the inner and outer rotors
(analogous to the main and gate rotors in a conventional screw machine) creates a series of
separate working chambers. In this type of machine the rotors have parallel axes of rotation, and if both rotors are free to rotate about their own axes, these axes can be fixed in space. The use of ported end plates is proposed to control the period during which fluid is
allowed to enter or leave the working chambers of the internally geared screw machine. As with conventional screw machines, these internally geared rotors can then be used to achieve compression or expansion of a trapped mass of fluid, and the machine geometry can be designed in order to optimise performance for particular applications. This paper describes the geometrical analysis of some simple rotor profiles and explores the effect on rotor torques for particular applications of this novel screw configuration.

Publication Type: Article
Additional Information: This is an author-created, un-copyedited version of an article published in IOP Conference Series: Materials Science and Engineering. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. This article is published under a CC BY licence. The Version of Record is available online at
Departments: School of Science & Technology > Engineering
SWORD Depositor:
[thumbnail of compressors_2017_mgr_2.pdf]
Text - Accepted Version
Available under License Creative Commons: Attribution 3.0.

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