Patent ID: 9739348
Date: 2017-08-22
CPC Classifications: F01L,F16H

Claim:
1. A tensioner device for tensioning a closed loop-type drive element, comprising: a housing defining a bore; a plunger disposed in said bore, said plunger including a hollow portion and a radially extending flange; a spring engaged within the hollow portion of the plunger for biasing the plunger in an outward direction; the housing including a first oil chamber disposed on a first side of the radially extending flange and connected to a first oil passage in communication with the first oil chamber for delivering pressurized oil to the first oil chamber, wherein when the first oil chamber is pressurized the pressurized oil applies a counter force opposing a force of the spring, the housing including a second oil chamber disposed on a second side of the radially extending flange and in communication with the hollow portion of the plunger and connected to a second oil passage in communication with the second oil chamber for delivering pressurized oil to the second oil chamber, wherein when the second oil chamber is pressurized the pressurized oil applies a force adding to the force of the spring, wherein the closed loop drive element is engaged with a plurality of pulleys or sprockets of an internal combustion engine and further comprising a controller for detecting a rotational speed of the internal combustion engine and a control valve selectively controlled by the controller for selectively supplying the pressurized oil to one of the first and second oil chambers when the internal combustion engine is operated in predetermined speed ranges.