A belt drive system for an internal combustion engine rotatably coupled to a rotary motor is provided. The internal combustion engine includes at least three cylinders each having a piston operable to turn a crankshaft. The belt drive system includes a belt and a controller. The belt is coupled to crankshaft of the internal combustion engine and the rotary motor; and the controller is operatively connected to the rotary motor, wherein the controller causes data processing hardware to perform the following operations: apply a torque to the rotary motor; and change the torque of the rotary motor prior to a change in a rotary speed of the internal combustion engine to maintain a predetermined tension in the belt and reduce a rotary motor torsional response through the belt drive to the torsional vibration input from the internal combustion engine.

A variable belt tensioner for an engine includes: a first damper; and a second damper connected to the first damper through a driver. The first damper, the second damper, and the driver causes a belt connected to a crankshaft pulley and a starter-generator pulley to have a first tensile strength when the engine including the crankshaft pulley starts, the first damper, the second damper, and the driver causes the belt to have a second tensile strength that is less than the first tensile strength when an electric power is generated by the starter-generator pulley, and the first damper, the second damper, and the driver causes the belt to have a third tensile strength that is less than the second tensile strength when the vehicle is accelerated by the engine.

Methods and systems are provided for identifying degradation of a belt-driven integrated starter generator (BISG) active belt tensioner coupled to a vehicle engine. By using the monitored change in FEAD load to compare the actual state of the tensioner (either in retracted or extended state) relative to the commanded state, the presence of excess belt tension may be distinguished from the presence of insufficient belt tension. Timely diagnosis of a belt tensioner may be improve belt health and extend fuel economy benefits of a BISG system.

A control apparatus for an internal combustion engine is provided which works to control an electric motor to start the engine through a belt transmission system. The control apparatus restricts rotation of the electric motor so as to keep a speed of the electric motor below a speed at which the electric motor is capable of producing a maximum torque until a given period of time passes since the electric motor is actuated to start in the motor mode. This enables the electric motor to generate the maximum torque when it is required to crank the engine.

A drive system for an agricultural work machine having a primary drive system configured to drive a performance system for performing a crop preparation or handling operation including a fluid motor, a fluid pump and a tensioner system. The fluid motor is configured to produce a drive force and to be driven by a flow of fluid moving through the motor. The fluid pump is operatively connected to the fluid motor and is configured to drive the fluid motor. The tensioner system is operatively connected to the fluid motor and to the fluid pump, wherein the direction of fluid flow through the fluid motor adjusts the application of at least one force applied to a belt in the drive system. The fluid motor is configured to adjust the force applied to the belt by regulating a belt tension in proportion to a torque provided by the fluid motor.

In one aspect the invention relates to a tensioner that is capable of precognitively anticipating when it is desirable to increase the tension in a belt or other endless drive element so as to prevent belt slip prior to events that would raise the risk of it.

A belt slip monitor system and method configured to determine whether a belt coupled to a motor-generator is slipping based on operational states of first and second movable portions of the belt slip monitor, wherein the operational states of the first and second movable portions are dependent upon the tension in the belt.

A camshaft-drive tensioner system is disclosed for an internal combustion engine having a camshaft-drive element. The camshaft-drive tensioner system includes a tensioner configured to be energized by a pressurized fluid in order to apply a force to the camshaft-drive element. The camshaft-drive tensioner system also includes a fluid pump configured to supply the pressurized fluid. The camshaft-drive tensioner system additionally includes a controller configured to regulate either volume or pressure of the fluid supplied to the tensioner by the fluid pump to thereby selectively vary the force applied to the camshaft-drive element. An internal combustion engine having such a camshaft-drive tensioner system and a method of selectively varying a force applied to the camshaft-drive element are also disclosed.

A tensioner device for a belt or chain defines a housing defining a bore with a plunger disposed in the bore. A spring is engaged with the plunger for biasing the plunger in an outward direction. The housing further includes an oil chamber connected to an oil passage in communication with the oil chamber for delivering pressurized oil to the oil chamber, wherein when the oil chamber is pressurized the pressurized oil applies a counter force opposing a force of the spring.

Methods and systems are provided for tensioning a belt of a belt drive of an internal combustion engine. In one example, a movable tensioning means assigned to an active tensioner is provided, which applies a force to a belt of a belt drive, and the active tensioner is controlled such that a compression of a spring of the tensioner is at least countered, so that a movement of the tensioning means under the load of the belt is at least hindered. The belt is then excited to vibration in a contact zone between the belt and the movable tensioning means by use of a starter so that the tensioning means exposed to the force of the spring is moved further in the direction of the belt under expansion of the spring, whereby the belt is tensioned.