Patent ID: 9651156
Date: 2017-05-16
CPC Classifications: F16J

Claim:
1. A mechanical seal sealing a space between a housing of an apparatus and a rotary shaft penetrating through a bore formed in said housing, comprising: a rotary ring provided on said rotary shaft and formed with a seal face at an end face of an atmosphere side in an axial direction; a stationary ring formed with a seal face at an end face on an inside in the axial direction, said seal face of said stationary ring contacting and sliding against said seal face of said rotary ring whereby said stationary ring is pressed towards said rotary ring by springs; a casing provided with said stationary ring, said casing placed around said bore of said housing and storing said rotary ring in an inner space of said casing; a cooler solution inlet bore penetrating in between an outer peripheral portion of said casing and said inner space thereof, said cooler solution inlet bore providing a cooler solution to said inner space of the casing from an outside of said casing; a tubular member placed around the stationary ring along an inner circumferential face defining the inner space of the casing and placed within the inner space of the casing, and the tubular member guiding the cooler solution into the inner space of the casing via the cooler solution inlet bore and to an outer circumferential side of the seal face of each of the rotary seal ring and the stationary seal ring; a cooler solution introduction opening formed in the tubular member and introducing the cooler solution near the seal faces of the rotary seal ring and the stationary seal ring, wherein the cooler solution is provided to the inner space of the casing via the cooler solution inlet bore and flows along an outer circumferential face of the tubular member; a cooler solution outlet bore penetrating in between an outer circumferential face of said casing and said inner space thereof, said cooler solution outlet bore discharging said cooler solution to said outside of said casing from said inner space of the casing; a seal collar with a circular ring shape fixed to said rotary shaft, said seal collar contacting a back of said rotary ring to regulate movement of said rotary ring towards the inside in the axial direction and determine a position of said rotary ring in the axial direction; a partial impeller formed on an outer peripheral portion of said seal collar, said partial impeller having a plurality of partial impeller grooves extending from an end face of one side of said seal collar to an outer circumferential face of said seal collar, said partial impeller grooves formed equally along a circumferential direction of an outer circumference of said seal collar to direct a flow of said cooler solution to the outer circumferential side of the seal faces of said rotary ring and said stationary ring, where said seal face of said stationary ring and said seal face of said rotary ring closely contact and slide against each other; and a ring-shaped cooler solution discharge groove formed on an inner periphery of said casing opposing said partial impeller, said cooler solution discharge groove defining an annular groove formed on the inner periphery of said casing; wherein said seal collar prevents said rotary ring from moving towards the inside in the axial direction and fixes an axial position of said rotary ring to said rotary shaft even if said rotary ring is pressed by a pressing force of said springs of said stationary ring; wherein each of said partial impeller grooves is a groove having a shape that is a cylinder cut with an angle so that a cross section of each groove at an atmosphere side end face of said seal collar is approximately a half-circle shape, and wherein each of said partial impeller grooves gradually becomes shallower towards an inside end face of said seal collar; and wherein said cooler solution discharge groove is divided by a dam so as to prevent said cooler solution discharge groove from forming a communicated circular passage, and said dam has a predetermined width covering said cooler solution discharge groove in a width direction; wherein, at a part which is a base face of said cooler solution discharge groove and at a front part of said dam along a rotating direction of said rotary shaft, an opening on an inner space side of said cooler solution outlet bore is formed, a ratio (Lgs/Ldl) of a projecting distance (Lgs) of a projecting portion of a tip portion of each partial impeller groove of the partial impeller against a width (Ldl) of the cooler solution discharge groove at the casing is more than 0 and 0.65 or less, said projecting portion of the tip portion being a portion that projects axially beyond the cooler solution discharge groove; and a ratio (Lgw/Lgd) of a maximum width (Lgw) of each of said partial impeller grooves to a maximum depth (Lgd) of each of the partial impeller grooves is 2.0 or more and 5.0 or less.