Patent ID: 6290470
Filing Date: 2001-09-18
Classification: F04B,F16J

Abstract:
A shaft sealing assembly for a rotary shaft extending through and supported by a housing, wherein the assembly prevents fluid from leaking out of the housing, the sealing assembly comprising:a first lip ring placed around the shaft, the first ring having a first peripheral portion, which extends in a substantially radial direction with respect to the shaft, and a first lip portion that contacts the surface of the shaft, wherein the first lip portion resiliently contacts the surface of the shaft and has a first and second surface, the first surface being located on an inner side of the first lip portion, and the second surface being located on an outer side of the first lip portion, and wherein the first surface forms a smaller angle than the second surface with respect to the shaft to prevent leakage of fluids from the inside of the housing when the shaft is stopped and allows leakage of fluids from the inside of the housing when the shaft rotates;a retainer ring placed adjacent to the first lip ring around the shaft, the retainer ring having a second peripheral portion that extends in a substantially radial direction with respect to the shaft, wherein the retainer ring supports the first lip ring so that the first ring substantially retains its shape;a second lip ring placed around the shaft and adjacent to the retainer ring on the opposite side of the retainer ring from the first lip ring, the second lip ring having a third peripheral portion that extends in a substantially radial direction with respect to the shaft and a second lip portion that extends substantially along the surface of the shaft, wherein the second lip portion resiliently contacts the surface of the shaft to substantially prevent leakage of fluids from the inside of the housing; anda case for holding the rings together by gripping the first, the second, and the third peripheral portions;wherein the first and third peripheral portions extend outwardly beyond the second peripheral portion to provide an annular contact area, the first and second lip rings resiliently contact one another in the contact area, and wherein at least one of the first and the second lip rings has an angular projection formed in the annular contact area, wherein total projection thickness as measured in the axial direction prior to assembly is greater than that of the second peripheral portion.