TENSIONER FOR ENDLESS TRANSMISSION BELT AND INTERNAL COMBUSTION ENGINE HAVING THE TENSIONER

摘要

A tensioner for an endless transmission belt includes a plunger body. A plunger is movably provided in a hole of the plunger body to press the belt. A chamber is provided between the plunger and the plunger body to store hydraulic oil. An oil supply passage is provided in the plunger body to supply the oil from an oil pump to the chamber. A check valve is provided between the chamber and the passage and configured to allow the oil to be supplied from the pump to the chamber while the check valve is configured to be closed when a pressure in the chamber is higher than a pressure of the oil supplied by the pump. A relief valve is provided between the chamber and the passage and configured to discharge the oil in the chamber to the passage when the pressure in the chamber exceeds a first predetermined value.