Abstract: An inside-type mechanical seal is mounted between a rotating shaft and a housing, and adapted for preventing leakage of a sealed fluid from an outer circumference of a sliding surface in the direction of an inner circumference thereof, wherein provided are a rotary-side sealing ring mounted on a rotating shaft side, a stationary-side sealing ring mounted on a seal case side, an annular packing for pushing the stationary-side sealing ring toward the rotary-side sealing ring, a holding part on the outer circumferential side being fitted in the seal case, and a seal lip part on the inner circumferential side being in close contact with the stationary-side sealing ring, and wherein provided to the seal case is a ring-shaped projection abutting against a back surface of the packing during assembly of the mechanical seal, and adapted for pushing the packing toward the stationary-side sealing ring.

Abstract: Provided is a mechanical seal that ensures the flow rate of a cooling fluid, which is necessary to cool a slide seal surface, and that can prevent erosion from occurring. In the mechanical seal, the ratio between the depth and the width of each groove of a partial impeller is 2.0-5.0; the ratio of the distance between the grooves of the partial impeller to the width of a weir of a casing is 0.5-3.1; the ratio of the total length of the widths of the grooves of the partial impeller to the total length of the peripheral surface of the partial impeller, in which the grooves are formed, is 0.28-0.8; or the ratio of the length of the projected portion of the tip of each groove of the partial impeller to the width of a cooling liquid discharging groove of the casing is greater than 0 and less than or equal to 0.65.

Abstract: An inside-type mechanical seal is mounted between a rotating shaft and a housing, and adapted for preventing leakage of a sealed fluid from an outer circumference of a sliding surface in the direction of an inner circumference thereof, wherein provided are a rotary-side sealing ring mounted on a rotating shaft side, a stationary-side sealing ring mounted on a seal case side, an annular packing for pushing the stationary-side sealing ring toward the rotary-side sealing ring, a holding part on the outer circumferential side being fitted in the seal case, and a seal lip part on the inner circumferential side being in close contact with the stationary-side sealing ring, and wherein provided to the seal case is a ring-shaped projection abutting against a back surface of the packing during assembly of the mechanical seal, and adapted for pushing the packing toward the stationary-side sealing ring.

Abstract: Provided is a mechanical seal that ensures the flow rate of a cooling fluid, which is necessary to cool a slide seal surface, and that can prevent erosion from occurring. In the mechanical seal, the ratio between the depth and the width of each groove of a partial impeller is 2.0-5.0; the ratio of the distance between the grooves of the partial impeller to the width of a weir of a casing is 0.5-3.1; the ratio of the total length of the widths of the grooves of the partial impeller to the total length of the peripheral surface of the partial impeller, in which the grooves are formed, is 0.28-0.8; or the ratio of the length of the projected portion of the tip of each groove of the partial impeller to the width of a cooling liquid discharging groove of the casing is greater than 0 and less than or equal to 0.65.