Bombardier Recreational Products Inc.

Consortium De Recherche Brp - Université De Sherbrooke S.e.n.c.

David Monfette

Michel Bernier

Normand Lebreux

Roger Rioux

Bruno Schuehmacher

Jasmin Rouleau

Marc Gagnon

Eric Lafreniere

Jean-Philippe Desbiens

Gilbert Lefrancois

Daniel Duceppe

Garrett Morgan

A method for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft is disclosed. The method includes: sensing a voltage of a capacitance connected to the ETM and configured to power the ETM; detecting a rotation of the crankshaft resulting from an actuation of a recoil starter; in response to detecting the rotation of the crankshaft, determining if an assisted start condition is met; in response to the assisted start condition being met, delivering power from the capacitance to the ETM and the ETM assisting the recoil starter; in response to the assisted start condition not being met, continuing to turn the crankshaft with the recoil starter without assistance from the ETM; determining if the ICE has started; and in response to the ICE being started, delivering power from the ETM to the capacitance.

Method and system for starting an internal combustion engine

A method for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft comprises energizing an absolute position sensor adapted for providing an indication of an angular position of a rotor of the ETM and applying a current to the ETM to generate a sufficient torque to rotate the crankshaft.

An electric turning machine (ETM) operatively connected to an internal combustion engine (ICE) is operated as a motor with a first control strategy and as a generator with a second control strategy. In the first control strategy, electric power is delivered from a power source to the ETM selectively through at least one transistor of an electrical converter. After switching from the first control strategy to the second control strategy, the ETM delivers electric power to an accessory selectively through the at least one transistor of the electrical converter.

Method for operating an electric turning machine operatively connected to an internal combustion engine

An internal combustion engine (ICE) includes a crankshaft, a cylinder head defining in part a variable combustion chamber of the ICE, a direct fuel injector mounted on the cylinder head, a power source, an electric turning machine (ETM) rotating the crankshaft, an absolute position sensor providing an indication of an angular position of a rotor of the ETM, and an engine control unit (ECU) operatively connected to the absolute position sensor. The ECU controls a delivery of electric power from the power source to the ETM based on the angular position of the rotor of the ETM and causes the direct fuel injector to inject fuel directly in the combustion chamber at a time selected based on the angular position reached by the rotor of the ETM.

A method for controlling delivery of electric power between a power source and an electric turning machine (ETM) comprises applying a start signal to a start-up power electronic switch to cause turning on of the start-up power electronic switch and to allow delivery of electric power from the power source to the ETM via the start-up power electronic switch. A recharge signal is applied to a run-time power electronic switch to cause turning on of the run-time power electronic switch for delivery of electric power from the ETM to the power source via the run-time power electronic switch. A circuit comprises a discharging circuit including the start-up power electronic switch for delivering the electric power when the start-up power electronic switch is turned on. A charging circuit includes the run-time power electronic switch for delivering the electric power when the run-time power electronic switch is turned on.

A method and a system for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft are disclosed. An absolute angular position of the crankshaft related to a top dead center position of a piston in a combustion chamber of the ICE is determined. Electric power is delivered to the ETM at a first level to rotate the crankshaft. Electric power is then delivered to the ETM at a second level greater than the first level when the piston reaches a predetermined position before the TDC position. Fuel is injected in the combustion chamber after the piston has passed beyond the TDC position. The fuel is then ignited. In an implementation, the ICE is started in less than 110 degrees of rotation of the crankshaft.

A method and a system for operating an electric turning machine (ETM) operatively connected to an internal combustion engine (ICE) are disclosed. The ETM operates as a motor with a first control strategy and as a generator with a second control strategy, the second control strategy being distinct from the first control strategy. The system comprises an engine control unit adapted for controlling an operation of the ETM according to the first and second control strategies. Electric and assisted start procedures are available for starting the ICE by delivering electric power from a power source to the ETM which is co-axially mounted to a crankshaft of the ICE. Assisted start includes delivering the electric power to the ETM while a recoil starter is used to rotate the crankshaft. A manual start procedure is also available. The power source is charged by the ETM when the ICE is running.

A method for operating an electric turning machine (ETM) operatively connected to an internal combustion engine (ICE) are disclosed. An engine control unit (ECU) controls the ETM to operate as a motor with a first control strategy and as a generator with a second control strategy. The second control strategy is distinct from the first control strategy. The ECU controls switching the operation of the ETM from the first control strategy to the second control strategy when a sensor senses that a rotational speed of the ICE is equal to or above a minimum revolution threshold.

A method of shutting down an off-road vehicle is provided. The vehicle includes two rear wheels, two front wheels, a motor selectively operatively connected to the wheels, a front driveshaft selectively connected to the motor to selectively drive the two front wheels, and a rear driveshaft connected to the motor to drive the two rear wheels. The method includes: interrupting operation of the motor; and automatically operatively connecting the front driveshaft to the motor once the operation of the motor has been interrupted.

Electric off-road wheeled vehicle

A driving pulley for a CVT has a shaft, a fixed sheave mounted on the shaft, a first sleeve disposed around the shaft and being operatively connected to the shaft, a movable sheave mounted on the first sleeve, a second sleeve disposed around the first sleeve and being connected to the shaft, a spring biasing the movable sheave away from the fixed sheave, and a CVT chamber having an annular cross-section. The fixed and movable sheaves are adapted to receive a belt therebetween. The CVT chamber has at least one opening adapted for fluidly communicating the CVT chamber with a hydraulic fluid reservoir. Hydraulic pressure in the CVT chamber biases the movable sheave toward the fixed sheave. The CVT chamber has an inner wall formed by the first sleeve, an outer wall formed by the second sleeve, an outer end, and an inner end formed by the movable sheave.

Driving pulley for a continuously variable transmission

A vehicle powertrain has an engine, a driving shaft having a passage defined therein, a driven shaft, a pump, a hydraulic fluid reservoir, and a CVT. A driving pulley of the CVT includes a fixed sheave and a movable sheave disposed on the driving shaft for rotation therewith, a spring biasing a movable sheave away from the fixed sheave, and a CVT chamber fluidly communicating with the passage of the driving shaft. The pump supplies hydraulic fluid from the reservoir to the passage in the driving shaft. The hydraulic fluid flows from the passage to the CVT chamber to create a hydraulic pressure in the CVT chamber. The hydraulic pressure in the CVT chamber biases the movable sheave toward the fixed sheave.

Vehicle powertrain having a hydraulic continuously variable transmission

An off-road vehicle has four wheels and side-by-side driver and passenger seats. At least two of the wheels are driven by an electric motor powered by batteries disposed in the vehicle.

A method of controlling a hydraulic CVT of a vehicle comprises: determining a speed of rotation of a driving shaft; determining a speed of rotation of a driven shaft; determining a ratio of the speed of rotation of the driving shaft versus the speed of rotation of the driven shaft; determining an engine torque; determining a base clamping force to be applied by the driving pulley onto the belt based on the ratio and the engine torque; determining a desired speed of rotation of the driving shaft; determining a corrective clamping force by comparing the speed of rotation of the driving shaft to the desired speed of rotation of the driving shaft; and controlling a hydraulic pressure applied to a movable sheave to apply a sum of the base and corrective clamping forces onto the belt. A vehicle having a CVT controlled by the method is also disclosed.

Method of controlling a hydraulic continuously variable transmission

A method of controlling a hydraulic CVT of a vehicle includes: determining a speed of rotation of a driving shaft; determining a speed of rotation of a driven shaft; determining a ratio of the speed of rotation of the driving shaft versus the speed of rotation of the driven shaft; determining an engine torque; determining a base clamping force to be applied by the driving pulley onto the belt based on the ratio and the engine torque; determining a desired speed of rotation of the driving shaft; determining a corrective clamping force by comparing the speed of rotation of the driving shaft to the desired speed of rotation of the driving shaft; and controlling a hydraulic pressure applied to a movable sheave to apply a sum of the base and corrective clamping forces onto the belt. A vehicle having a CVT controlled by the method is also disclosed.

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Linz, Austria

David Monfette