Pair of sliding components

A rotating machine having a leakage side space and a sealed fluid space in which a sealed fluid is housed, and comprising:

• a housing;
• a rotary shaft;
• a first sliding component fixed to one of the housing and the rotary shaft and having a sliding surface;
• and
• a second sliding component fixed to the remaining one of the housing and the rotary shaft and having a sliding surface sliding with the sliding surface of the first sliding component,
• wherein the sliding surface of the first sliding component is provided with a plurality of first positive pressure generation grooves each having an opening which is opened to a leakage side of the first sliding component, extending from the opening in a relative rotation direction of the second sliding component with respect to the first sliding component, and having closed terminating end portions configured to generate positive pressure,
• wherein the sliding surface of the first sliding component having an inner diameter equal to an inner diameter of the sliding surface of the second sliding component;
• wherein the sliding surface of the first sliding component having an outer diameter equal to an outer diameter of the sliding surface of the second sliding component;
• wherein the first positive pressure generation groves are separated from each other by part of a land which forms part of the sliding surface of the first sliding component,
• wherein the sliding surface of the second sliding component is provided with a plurality of second positive pressure generation grooves each having an opening which is opened to the leakage side of the second sliding component, extending from the opening of each of the second positive pressure generation grooves in a relative rotation direction of the first sliding component with respect to the second sliding component, and having closed terminating end portions configured to generate positive pressure,
• wherein the second positive pressure generation groves are separated from each other by part of a land which forms part of the sliding surface of the second sliding component,
• wherein the sliding surfaces of the first sliding component and the second sliding component slide on each other at least in such a manner that the first positive pressure generation grooves and the second positive pressure generation grooves overlap and intersect with each other,
• wherein at least part of the second positive pressure generation grooves communicating with the leakage side have radial lengths larger than radial lengths of the first positive pressure generation grooves communicating with the leakage side,
• wherein the closed terminal ends of all of the second positive pressure generation grooves are disposed on the sealed fluid side in a radial direction with respect to the closed terminal ends of all of the first positive pressure generation grooves,
• wherein at least two of the second positive pressure generation grooves are arranged to intersect with each of the first positive pressure generation grooves,
• wherein all of the first positive pressure generation grooves and all of the second positive pressure generation grooves obliquely extend in a circumferential direction from the leakage side toward a sealed fluid side,
• wherein the volume of each of the first positive pressure generation grooves is smaller than the volume of each of the second positive pressure generation grooves,
• wherein all of the grooves of the first pressure generating grooves are of the same radial length relative to one another,
• wherein all of the grooves of the second pressure generation grooves are of the same length relative to one another, and
• wherein the radial lengths of all of the second positive pressure generation grooves communicating with the leakage side is larger than the radial lengths of all of the first positive pressure generation grooves communicating with the leakage side.