Tensioner with spring force control in a second bore

A tensioner for a passive tensioner system tensioning a span of chain or a belt, comprising:

• a housing having a first axially extending bore with a first fluid input, and a second axially extending bore with a second fluid input;
• a first piston slidably received by the first axially extending bore, the first piston comprising a body having a first end and a second end;
• a first pressure chamber for biasing the first piston outwards from the housing, defined between the first piston and the first axially extending bore and in fluid communication with the first fluid input;
• a hollow moveable sleeve slidably received by the second axially extending bore, comprising a hollow body having a first open end and a second open end separated by an inner flange having a top surface and a bottom surface;
• a second piston having a body coaxially arranged within the moveable sleeve and received by the first open end of the movable sleeve;
• a second piston spring for biasing the second piston outwards from the moveable sleeve, received by the first open end of the moveable sleeve, having a first end contacting the second piston and a second end contacting the top surface of a flange of the moveable sleeve;
• a bias spring for biasing the moveable sleeve outwards from the housing, received within the second open end of the moveable sleeve with a first end of the bias spring in contact with the bottom surface of the inner flange of the moveable sleeve and a second end in contact with the second axially extending bore of the housing;
• a second pressure chamber defined between the bottom surface of the inner flange of the moveable sleeve and the second bore, in fluid communication with the second fluid input;
• and
• a check valve between the second pressure chamber and the second fluid input;
• wherein when dynamic load from the chain or belt moves the first piston and the second piston inwards and outwards from the housing, fluid from the second fluid input is drawn into the second pressure chamber through the check valve, creating a fluid pressure in the second pressure chamber, causing the movable sleeve to move outwards from the housing and exert an outward force on the second piston through the second piston spring, opposing an inward force of the dynamic load.