Sliding component

1. A sliding component comprising a first annular sliding part and a second annular sealing part that have a first sealing face and a second sealing face, respectively, the first sealing face and the second sealing face being relatively slidable to each, other, the first sealing face is provided with:

radial-direction grooves communicating with a high-pressure fluid side through the outer periphery of the first annular sliding part but isolated from a low-pressure fluid side by a seal area;

an annular pressure release groove communicating with the high-pressure fluid side through the radial-direction grooves but isolated from the low-pressure fluid, side by the seal area:

first pumping grooves each communicating with the high-pressure fluid side through the annular pressure release groove and the radial-direction grooves but isolated from the low-pressure fluid side by the seal area and also angled to discharge a fluid toward the high-pressure fluid side by sliding relative to the second sealing face,

second pumping grooves each communicating with the low-pressure fluid side through an inner periphery of the first annular sliding part but isolated from the high-pressure fluid side by the seal area and, also angled to discharge the fluid toward the high-pressure fluid side by sliding relative to the second sealing face,

positive-pressure generation grooves configured to generating positive-pressure by sliding relative to the second sealing face, the positive pressure generation grooves each indirectly communicating with the high-pressure fluid, side through the radial-direction grooves and also directly communicating with the high-pressure fluid side through the outer periphery of the first annular sliding part, and

the positive-pressure generation grooves having width in a circumferential direction that is longer than width in the circumferential direction of the radial-direction grooves.

2. A sliding component as set forth in claim 1 , wherein the positive-pressure generation grooves each comprises a Rayleigh step mechanism.

3. A sliding component as set forth in claim 1 , wherein at least one of the first pumping grooves and at least one of the second pumping grooves adjacent to each other are formed in such a manner that a portion of the at least one of the first pumping grooves on the low-pressure fluid side and a portion of the at least one of the second pumping grooves on the high-pressure fluid side overlap as viewed both in a radial direction and in the circumferential direction.

4. A sliding component as set forth in claim 3 , wherein the first pumping grooves and the second pumping grooves constitute multiple pairs of pumping grooves each formed by one of the first pumping grooves and one of the second pumping grooves adjacent to each other, and wherein

each of the multiple pairs of pumping grooves are formed in such a manner that a portion of the one of the first pumping grooves on the low-pressure fluid side and a portion of the one of the second pumping grooves on the high-pressure fluid side overlap as viewed both in a radial direction and in the circumferential direction.

5. A sliding component as set forth in claim 4 , wherein the multiple pairs of pumping grooves are arranged at intervals in an circumferential direction, each of the intervals being larger than a distance in the circumferential direction between the first pumping groove and the second pumping groove of each of the multiple pair of pumping grooves.