Patent ID: 9534636
Date: 2017-01-03
CPC Classifications: F16C,F16J,G01P

Claim:
1. A rolling bearing unit with a combination seal ring, comprising: a rotary side race ring and a stationary side race ring, relatively rotated in a state of being arranged concentrically with each other; multiple rolling elements disposed to be rollable between a rotary side race and a stationary side race, the rotary side race and the stationary side race being respectively disposed on a peripheral surface where the rotary side race ring and the stationary side race ring oppose each other; and a combination seal ring closing an end portion opening of a bearing internal space located between the peripheral surfaces where the rotary side race ring and the stationary side race ring oppose each other, the combination seal ring including a slinger and a seal ring, wherein: the slinger is fixedly fitted to a portion opposing the peripheral surface of the stationary side race ring within a portion of the peripheral surface of the rotary side race ring, the slinger has an annular shape whose cross-section has an L-shape, and the slinger includes: a rotary side cylindrical portion; and a rotary side annular portion radially bent from an axial end edge of the rotary side cylindrical portion toward the stationary side race ring; the rotary side cylindrical portion is fitted to the peripheral surface of the rotary side race ring to fix the rotary side cylindrical portion to the rotary side race ring; the seal ring is fixedly fitted to a portion opposing the slinger within a portion of the stationary side race ring, and the seal ring includes: a metal insert being fixedly fitted to the stationary side race ring; and an elastic member, whose proximal end portion is supported by the metal insert, having respective multiple seal lips; the metal insert has an annular shape whose cross-section has an L-shape, and the metal insert includes: a stationary side cylindrical portion; and a stationary side annular portion radially bent from an axial end edge of the stationary side cylindrical portion toward the rotary side race ring; the stationary side cylindrical portion is fitted to the peripheral surface of the stationary side race ring to fix the stationary side cylindrical portion to the stationary side race ring; a distal end portion of the respective seal lips is brought into sliding contact with a surface of the slinger over an entire periphery; a labyrinth seal is disposed between a distal end side peripheral edge of the rotary side annular portion and the peripheral surface of the stationary side cylindrical portion; an auxiliary seal lip is disposed integrally with the elastic member in a portion closer to the stationary side cylindrical portion than the respective multiple seal lips within a base of the elastic member, rigidity of the auxiliary seal lip is lower than one seal lip of the multiple seal lips close to an external space outside of the seal ring, the one seal lip being closest to the labyrinth seal within the respective multiple seal lips, and a distal end edge of the auxiliary seal lip is brought into sliding contact with or caused to closely oppose an axial side surface of the rotary side annular portion over the entire periphery; a thickness of the proximal end portion of the auxiliary seal lip is set to be one half to one fifth of a thickness of the proximal end portion of the one seal lip close to the external space; and the proximal end portion of the auxiliary seal lip is positioned in a portion closer to the rotary side annular portion than the proximal end portion of the one seal lip close to the external space, wherein: a peripheral surface of a side, having the stationary side annular portion within the stationary side cylindrical portion, is covered by the elastic member; both inner and outer peripheral edge portions of a portion covering an axial side surface of the stationary side annular portion within the elastic member, a portion covering the peripheral surface, and a base of the auxiliary seal lip are formed smoothly and continuously by a curved surface whose cross-section has a quarter arcuate shape; a thickened portion whose radial and axial thickness dimension is larger than a thickness dimension of other portions is disposed in a portion where one radial side and one axial side are partitioned by the peripheral surface of the stationary side cylindrical portion and the axial side surface of the stationary side annular portion, within a portion of the elastic member; a proximal end portion of the auxiliary seal lip is continuously formed in a portion close to the respective multiple seal lips in the radial direction within an axially inner end surface of the thicken portion; the axially inner end surface of the thickened portion and the portion covering the peripheral surface are formed as a curved surface whose cross-sectional shape is a quarter arcuate shape, and a radius of curvature R the axially inner end surface of the thickened portion and the base of the auxiliary seal lip are formed as a curved surface whose cross-sectional shape is a quarter arcuate shape, and a radius of curved R