| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve fuel economy by expediting the temperature rise of cooling water in an engine body and preventing the heat loss taken by the engine body when the temperature of the cooling water is low.SOLUTION: In a water pump for a vehicle, a rotating shaft with a pulley and an impeller attached to both axial ends comprises a first rotating shaft connected to the impeller and a second rotating shaft connected to the pulley. The first rotating shaft is connected to a temperature sensitive case containing a thermal expansion body. In the temperature sensitive case, there are provided a piston which reciprocates between the first rotating shaft and the second rotating shaft with expansion and contraction of the thermal expansion body, and a retainer transmitting rotation between the piston and the first rotating shaft. A first friction plate is attached to the piston, a second friction plate is attached to the second rotating shaft, and the first friction plate and the second friction plate are set to be in a contact state or in a non-contact state with the expansion and contraction of the thermal expansion body.</p> |
