An electric vehicle comprises a drive belt mounted about a motor output and about a drive wheel. The drive belt is driven by an output torque and experiences the output torque in a first torque direction and in a second torque direction. A belt tensioner comprises a tension pulley in contact with the drive belt, and a tensioning mechanism configured to displace the tension pulley in a first direction against the drive belt to tension the drive belt upon the drive belt experiencing the output torque in the first torque direction. The tensioning mechanism is configured to allow tension in the drive belt to displace the tension pulley in a second direction opposite to the first direction upon the drive belt experiencing the output torque in the second torque direction.

The tensioning pulley arrangement for a belt drive in an engine, is provided. In one example, the tensioning pulley arrangement includes a first tensioning pulley and a second tensioning pulley tensioning a belt with a spring force and a spring preload force generated by a first spring device coupled to the first and second tensioning pulleys. The tensioning pulley arrangement further includes an intensifying device that decreases belt tension during low belt load conditions and increases belt tension during high belt load conditions. In this way, friction losses during low belt loads may be reduced and belt slippage caused by high belt loads and/or dynamic shifts in belt loads may also be reduced.

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 yard maintenance device having a working assembly selectively rotatable based on operation of an engine of the device may include a belt drive system. The belt drive system may include at least one driven pulley operably coupled to the working assembly, a drive shaft operably coupled to the engine, a drive belt configured to selectively couple the drive shaft to the at least one driven pulley, a tension adjustment assembly, and a control unit. The tension adjustment assembly may be configured to operably couple to at least one component of the belt drive system to adjust a position thereof to modify tension of the drive belt. The control unit may be configured to provide electronic control of the tension adjustment assembly.

A vehicle includes a chain tensioner that serves as an oil damper using oil supplied from an oil pump. The vehicle includes a controller that controls a traveling mode of the vehicle in a BEV mode or a non-BEV mode. When shifting the traveling mode from the BEV mode to the non-BEV mode, the controller executes a high-pressure process for calculating a supply pressure of oil supplied to the chain tensioner that is higher when a duration of the BEV mode is greater than or equal to a specified time than when the BEV mode duration is less than the specified time.

The disclosure relates to a method for detecting belt slip of a belt drive driving a generator of an internal combustion engine, said belt drive having a belt tensioner that can be adjusted in operation and adjusts the pre-tensioning force of the belt according to the detected belt slip. According to said method, the rotational speed profile of the crankshaft is recorded during an angular window of the crankshaft of m.Math.360 degrees and an average value of the crankshaft rotational speed is formed from said rotational speed profile; temporally independently from the recording of the rotational speed profile of the crankshaft, the rotational speed course of the generator shaft is recorded during an angular window of the generator shaft of n.Math.u.sup.−1.Math.360 degrees and an average value of the generator shaft rotational speed is formed from said rotational speed profile.

An internal-combustion engine includes a belt-driven starter generator and makes an idling stop while a vehicle is at a stop. In the process of the engine revolution speed decreasing with cutting of fuel to stop the vehicle, to suppress the reduction in restart responsiveness caused by slack in a belt, preliminary powering of the starter generator is performed. The belt tension during deceleration microscopically changes periodically between a relatively high-tension period and a relatively low-tension period due to pulsation of the engine revolution speed. Slack in the belt does not occur in the high tension period, and thus preliminary powering torque is applied only in the low-tension period.

Systems and methods for detecting and mitigating belt slip of an engine front end accessory drive are described. In one example, three different signals are input to a weighted average filter to determine the presence or absence of belt slip so that quality of an indication of belt slip may be improved.

A work vehicle having an implement includes an engine control unit for controlling an engine and detecting an abnormal state of the engine, a PTO transmission mechanism for transmitting power from the engine to the implement, a PTO clutch for switching ON/OFF power transmission by the PTO transmission mechanism and a clutch control circuit configured to render the PTO clutch OFF based on a detection signal outputted by the engine control unit at time of detection of the abnormal state.

An internal-combustion engine includes a belt-driven starter generator and makes an idling stop while a vehicle is at a stop. In the process of the engine revolution speed decreasing with cutting of fuel to stop the vehicle, to suppress the reduction in restart responsiveness caused by slack in a belt, preliminary powering of the starter generator is performed. The belt tension during deceleration microscopically changes periodically between a relatively high-tension period and a relatively low-tension period due to pulsation of the engine revolution speed. Slack in the belt does not occur in the high tension period, and thus preliminary powering torque is applied only in the low-tension period.