Patent ID: 8047579
Filing Date: 2011-11-01
Classification: F16L

Abstract:
1. A ball-bearingless and needle-bearingless self-lubricating swivelling coupling for providing a swivellable interconnection in a load-sensing hydraulic circuit between first and second hydraulic lines containing a hydraulic fluid which provides lubrication, the swivelling coupling comprising: a housing comprising: internal surfaces comprising at least one radial surface and at least one axial surface, said internal surfaces defining a cavity having an open end; and a port having a bore therethrough in fluid communication with the cavity, the port being connectable to the first line; a male component having a bore therethrough, the male component comprising: a shank portion having a port connectable to the second line; and a flange portion extending radially outward from the shank portion, the male component being insertable within the cavity of the housing to enable the flange portion to cooperate with the at least one radial surface, and to enable the bore of the male component and the bore of the port of the housing to be in fluid communication, the flange allowing a leak so that the fluid from the bores is partially leaked between the flange and the internal surfaces; and a nut securable within the cavity of the housing and surrounding the shank portion to radially restrain the same, the nut having a projection extending axially and internally into the cavity for axially restraining the flange and allowing the leak between the flange and the housing internal surfaces, the nut also allowing the male component to rotate with respect to the housing and the nut about a longitudinal axis of the shank portion, thereby enabling the first and second lines to be swivellably interconnected; and a first sealing element partially housed in the nut and provided between and abuttable against the male component and the projection of the nut, and a second sealing element partially housed in the nut and provided between and abuttable against the shank portion and the nut, the first sealing element being in between the second sealing element and the flange portion so that the leak creates a first pressurized interstitial region between the bores and the first sealing element, and also creates a second pressurized interstitial region between the first and second sealing elements, such that the first and second pressurized interstitial regions experience an ebb and flow of the hydraulic fluid in response to variations in hydraulic pressure in the load- sensing hydraulic circuit.