Abstract: A joint structure of an annular member and a shaft member softer than the former is produced by(a) providing a shaft member with an oil spreading over its circumference, the shaft member having a plurality of discrete grooves, on its circumference in an inclined angular configuration about the axis of the shaft member, and(b) press fitting the annular member to the bore of the annular member with an interference such that the inner periphery of the annular member bore meshingly expands into the grooves. Press fitting proceeds under resilient deformation of the inner periphery of the annular member in the boundary friction state. A continuous oil film remains on the mating surfaces while securing firm joint.

Abstract: A variable-capacity water pump includes a pump impelled fixed to a rotatable shaft for forcibly feeding cooling water from a cooling water passage, a mechanical seal disposed behind the pump impeller, a temperature sensor such as a thermostat mounted on the rotatable shaft and disposed in the cooling water passage for detecting the temperature of the cooling water, a thrust shaft disposed coaxially with the rotatable shaft and axially movable by the temperature sensor, and a disk secured to the thrust shaft for axial movement therewith, the disk being axially movable by the temperature sensor for varying a range of operation of the pump impeller. In response to a variation in the temperature of the cooling water, the temperature sensor axially moves the thrust shaft and hence the disk to vary the range of operation of the impeller, thereby changing the quantity of the cooling water flowing through the water pump.

Abstract: A variable contact seal mechanism which includes a rotatable shaft, a seal body having a wall member, and a seal member having a cylindrical portion secured onto the rotatable shaft and a tongue portion resiliently slidably contacting the seal wall such that continuous resilient contact force of the tongue portion with the wall is changed in response to rotational speed of the shaft. A bearing member is utilized which rotatably supports the shaft along with a mechanical sealing mechanism mounted so as to surround the shaft wherein the seal member is disposed between the bearing and the mechanical sealing mechanism.