Sealing ring for hydraulic pump distributor

Sealing ring for a hydraulic pump distributor (1) designed for a hydraulic distributor (2) that a hydraulic pump (44) may comprise, the said distributor (2) comprising at least one pump stator distribution face (5) secured to a pump stator (3), the said distribution face (5) having a stator-side low-pressure sealing surface (12) from which there open at least two inlet-delivery ports (7) formed in the pump stator (3) and each of which communicates with at least one inlet-delivery duct (8) specific to it and likewise formed inside the said stator (3), the said distributor (2) also comprising at least one pump rotor feed face (6) secured to a pump rotor (4), the said feed face (6) having a rotor-side low-pressure sealing surface (13) from which there opens at least one orifice (9) communicating with a feed duct (10) formed inside the said rotor (4) whereas the stator-side low-pressure sealing surface (12) is positioned facing the rotor-side low-pressure sealing surface (13) so that the feed orifice (9) alternately finds itself facing one or other of the two inlet-delivery ports (7) at least once per revolution of the pump rotor (4), characterized in that it comprises:

• At least one continuous sealing ring (11) housed with a small amount of axial and/or radial clearance in a ring groove (16) formed in the pump stator (3) inside the surface area delimited by the stator-side low-pressure sealing surface (12), the said ring (11) having a stator-side ring face (23) housed inside the ring groove (16), and a rotor-side ring face (22) flush with the stator-side low-pressure sealing surface (12), whereas the inlet-delivery ports (7) open onto the said sealing surface (12) via the said groove (16), the said ring (11) being axially or radially wider than the said ports (7) so as to cover them and comprising, approximately in axial or radial alignment therewith, at least one distribution opening (21) passing right through the continuous sealing ring (11) in the direction of its thickness, the said opening (21) being able to place one of the two inlet-delivery ports (7) in communication with the feed orifice (9) when the latter is approximately facing the said port (7);
• At least one circumferential-contact boss (14) formed axially or radially on each side of the distribution opening (21), the said boss (14) having a circumferential line of contact (15) that can come into contact with the rotor-side low-pressure sealing surface (13);
• At least one compression-decompression track (24) formed on a certain angular sector of the rotor-side ring face (22), the said sector being positioned outside of that part of the said face (22) in which the radial distribution opening (21) is situated;
• At least one ring sealing lip (39) that may or may not be secured to the continuous sealing ring (11) and that performs axial or radial sealing between the said ring (11) and the ring groove (16);
• At least one compression-decompression sealing gasket (28) which performs sealing between the stator-side ring face (23) and the bottom and/or the axial or radial sides of the ring groove (16) and does so in the angular area defined by the angular sector over which the compression-decompression track (24) is formed;
• Rotation-proofing means (36) which keep the continuous sealing ring (11) in a fixed angular position in relation to the pump stator (3).