NTN Corporation (NTN), a Japan-based automotive parts supplier, has developed the ‘Compact Chain Tensioner for Low Fuel Consumption’. It is actually a hydraulic auto chain tensioner (chain tensioner) which maintains the appropriate tension of the timing chain of an automotive engine application. The developed product contributes to downsizing of the chain tensioner by simplifying the structure and for improving the fuel efficiency of the engine by drastically reducing the amount of oil required to operate the chain tensioner.
The chain tensioner automatically maintains the appropriate tension of the timing chain which synchronises and rotates the crankshaft and camshaft of an automotive engine. Hydraulic chain tensioners use oil supplied from an oil pump inside the engine to maintain chain tension. However, the customers have required to reduce the oil consumption in order to improve fuel efficiency since recent years. Also, the chain tensioner has a rush noise problem due to insufficient tension of chains. This is because the oil pumps and supply of oil stops at the engine stop, and insufficient supply of oil makes the insufficient tension at engine restart.
The newly developed ‘Compact Chain Tensioner for Low Fuel Consumption’ has been designed to simplify the structure, reduce the size and weight, and adopted the structure which stores the oil supplied and discharged from the inside. This enables the product to drastically reduce the amount of supplied oil needed while maintaining high reliability and durability compared to the conventional products. By reducing the amount of oil, the developed product can reduce the size of the oil pump, thereby reduce the load on the pump operation and contribute to improved fuel efficiency of the engine. In addition, with the structure which stores oil inside the tensioner, the developed product can maintain the tension of the chain with appropriate oil pressure immediately after the engine starts and suppresses rush noise due to insufficient tension of the chain.
NTN claims that the new chain tensioner improves low fuel consumption by adopting a new oil storage structure to reduce oil consumption by 1/10 compared with conventional products. They further claim that it comes with 18 percent reduction in the axial direction and 10 percent or more reduction in weight compared to conventional products.