Slipper lubrication in axial piston pumps

Kakoullis, Yiannis Polly (1979). Slipper lubrication in axial piston pumps. University of Birmingham. Ph.D.

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The performance of hydrostatic type slippers in axial piston pumps has been studied both experimentally and theoretically.

The experimental work covers measurements of slipper clearance, slipper pocket pressure and piston spin. These measurements were taken from typical axial piston pumps running under normal operating conditions using a data logging system. The effect of operating conditions was also investigated and the resulting trends are described and discussed.

In the theoretical work the behaviour of an idealised slipper was studied under steady state conditions. It was established that a flat slipper of this type does not work on a purely hydrostatic basis. Additional lift can be generated hydrodynamically if the slipper is suitably tilted; however, if the slipper is flat it cannot satisfy moment equilibrium. One mechanism which was found to satisfy load, flow as well as moment equilibrium was the presence of suitable amounts of non-flatness on the slipper loads. A parabolic type of non-flatness was simulated and the relationships between tilt, pocket pressure central clearance and minimum clearance were derived with respect to non-flatness.

In conclusion, the theory is applied to the design procedure and a method is presented which enables the optimum non-flatness and minimum clearance to be estimated at particular operating conditions.

Type of Work: Thesis (Doctorates > Ph.D.)
Award Type: Doctorates > Ph.D.
College/Faculty: Faculties (to 1997) > Faculty of Engineering
School or Department: School of Engineering, Department of Mechanical Engineering
Funders: None/not applicable
Subjects: T Technology > TJ Mechanical engineering and machinery


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