Abstract: A plain bearing (410) is fixed to a shaft hole (401) of an impeller (400) of the pump (100) so as to rotatably support the impeller (400) with respect to the shaft (300), and is restricted from moving in an axial direction by an annular restrictor (310) fixed to the shaft (300). On an end face (411) of the plain bearing (410) facing the restrictor (310), a lubrication groove (412) connecting a radially inner side and a radially outer side of the end face (411) to supply cooling water onto the end face (411) for lubrication, and a dynamic pressure generating groove (413) that introduces a flow of cooling water created by rotation of the impeller (400) to generate a dynamic pressure, are provided. The present bearing suppresses an increase in rotation torque of the impeller (400) during high speed rotation.

Abstract: A plain bearing (410) is fixed to a shaft hole (401) of an impeller (400) of the pump (100) so as to rotatably support the impeller (400) with respect to the shaft (300), and is restricted from moving in an axial direction by an annular restrictor (310) fixed to the shaft (300). On an end face (411) of the plain bearing (410) facing the restrictor (310), a lubrication groove (412) connecting a radially inner side and a radially outer side of the end face (411) to supply cooling water onto the end face (411) for lubrication, and a dynamic pressure generating groove (413) that introduces a flow of cooling water created by rotation of the impeller (400) to generate a dynamic pressure, are provided. The present bearing suppresses an increase in rotation torque of the impeller (400) during high speed rotation.

Abstract: The present invention provides a mechanical seal preventing the deformation of the cartilage and exhibiting a good sealing performance. In said mechanical seal, the deformation of the back portion of the cartilage due to the force from the pump housing is absorbed by forming a groove portion having cross section substantially a triangular shape at the back portion of the cartilage. As a result, the deformation hardly transfers to the area near the inner tube portion of the cartilage 16 and the inner tube portion of the back portion; and the relative position of the seal ring, and the bellows or so scarcely changes with respect to the structure of the mating ring or so on the side of the rotation axis, thus the assembling length and the assembled load of the mechanical seal does not change, which allows the mechanical seal to exhibit good sealing performance.

Abstract: The present invention provides a mechanical seal preventing the deformation of the cartilage and exhibiting a good sealing performance. In said mechanical seal, the deformation of the back portion 16d of the cartilage due to the force from the pump housing 3 is absorbed by forming a groove portion 16f having cross section substantially a triangular shape at the back portion 16d of the cartilage 16. As a result, the deformation hardly transfers to the area near the inner tube portion 16a of the cartilage 16 and the inner tube portion 16a of the back portion 16d; and the relative position of the seal ring 14, and the bellows 15 or so scarcely changes with respect to the structure of the mating ring 11 or so on the side of the rotation axis 2, thus the assembling length and the assembled load of the mechanical seal 9 does not change, which allows the mechanical seal 9 to exhibit good sealing performance.