POSITIVE DISPLACEMENT MACHINES AND METHODS OF INCREASING LOAD-CARRYING CAPACITIES THEREOF

摘要

Positive displacement machines and methods therefor capable of increasing a load-carrying capacity of a piston-cylinder lubrication interface of positive displacement machines having a cylinder block, a cylindrical bore defined in the cylinder block, a piston reciprocably disposed within the cylindrical bore, and a working fluid within the piston-cylinder lubrication interface to provide a load-bearing function between the piston and the bore wall of the cylinder bore. The method includes providing at least one circumferential groove on a bore wall of the cylindrical bore within the piston-cylinder lubrication interface having an opening facing the piston and that is in fluidic communication with the piston-cylinder lubrication interface so as to contain a portion of the working fluid, and operating the positive displacement machine such that the working fluid enters the cylindrical groove and promotes hydrostatic balancing of pressure of the working fluid within the piston-cylinder lubrication interface.

主权项

1. A positive displacement machine comprising:
a cylinder block adapted to be rotated about an axis of the positive displacement machine; a plurality of cylindrical bores defined in the cylinder block and surrounding the axis, each of the cylindrical bores having a bore wall and a port; a plurality of pistons reciprocably disposed within the cylindrical bores, each of the pistons defining a piston-cylinder lubrication interface with the bore wall of a corresponding one of the cylindrical bores and defining a displacement chamber within the cylindrical bore adjacent the port thereof; a working fluid located within the displacement chambers and within the piston-cylinder lubrication interfaces to provide a load-bearing function between the pistons and the bore walls of the cylinder bores; and a plurality of circumferential grooves located within the piston-cylinder lubrication interfaces, at least one of the grooves being located on the bore wall of each of the cylindrical bores, the grooves having an opening facing the pistons and in fluidic communication with the piston-cylinder lubrication interfaces so as to contain a portion of the working fluid, wherein the grooves promote hydrostatic balancing of pressure of the working fluid within the piston-cylinder lubrication interfaces and increase a load-carrying capacity of the working fluid within the piston-cylinder lubrication interfaces during operation of the positive displacement machine.