A mower drive belt tensioner arm includes an elongate body having a tension pulley to provide tension to a mower drive belt. One of a pair of rear draft towers on the mower deck supports the elongate body above the surface of the mower deck. A coil spring urges an end of the elongate body in a direction between the pair of draft towers. A pivotable belt keeper may be mounted to the tensioner arm without tools, and extends over the perimeter of the tension pulley.

A mower drive belt tensioner arm includes an elongate body having a tension pulley to provide tension to a mower drive belt. One of a pair of rear draft towers on the mower deck supports the elongate body above the surface of the mower deck. A coil spring urges an end of the elongate body in a direction between the pair of draft towers. A pivotable belt keeper may be mounted to the tensioner arm without tools, and extends over the perimeter of the tension pulley.

Described embodiments include a reconfigurable belt tensioner that can be used to add, remove, and/or reposition peripheral accessories of an engine installation, for example, in an automobile or another vehicle. The tensioner has a housing, an arm with an axle, and a spring installed in the housing. The axle is inserted into and fastened to the housing. The arm rotates around the axle. When the arm is rotated, the spring provides the force that tends to return the arm and the housing to the original position. The tensioner can be reconfigured by repositioning the spring relative to the housing and/or the arm, changing the angle between the housing and the arm. The tensioner may be used, for example, on an LS-based GM small-block engine, and allow operation with and without the air conditioning compressor or other accessories.

An air-cooled heat exchanger has a frame assembly, a plenum supported by the frame assembly, an engine and a fan assembly. The engine includes a drive shaft and the fan assembly includes a fan connected to a fan shaft. The fan assembly is configured to move air through the plenum. The air-cooled heat exchanger also includes a drive assembly connected between the engine and the fan assembly. The drive assembly has a fan shaft sheave connected to the fan shaft, a driver sheave connected to the drive shaft, an idler pulley, and a drive belt in contact with the fan shaft sheave, driver sheave and idler pulley. The air-cooled heat exchanger has an idler bearing adjustment mechanism that is configured to adjust tension on the drive belt by adjusting the position of the idler pulley relative to the drive belt.

An air-cooled heat exchanger has a frame assembly, a plenum supported by the frame assembly, an engine and a fan assembly. The engine includes a drive shaft and the fan assembly includes a fan connected to a fan shaft. The fan assembly is configured to move air through the plenum. The air-cooled heat exchanger also includes a drive assembly connected between the engine and the fan assembly. The drive assembly has a fan shaft sheave connected to the fan shaft, a driver sheave connected to the drive shaft, an idler pulley, and a drive belt in contact with the fan shaft sheave, driver sheave and idler pulley. The air-cooled heat exchanger has an idler bearing adjustment mechanism that is configured to adjust tension on the drive belt by adjusting the position of the idler pulley relative to the drive belt.

In an aspect, a tensioner is provided for an endless drive member, and includes a shaft-and-base unit, a tensioner arm, a pulley, and a tensioner spring. The shaft-and-base unit is mountable to be stationary relative to an engine, and includes a fastener aperture for a fastener. The tensioner arm is pivotable relative to the shaft-and-base unit about a tensioner arm axis. The pulley is rotatably mounted to the tensioner arm for rotation and is engageable with an endless drive member. The tensioner spring is positioned to urge the tensioner arm in a first direction relative to the shaft-and-base unit. The tensioner spring includes a plurality of coils that are arranged generally helically about a longitudinal axis and are spaced radially from one another and generally increase in distance away from the axis in a longitudinal direction.

A method of operating an accessory drive system for a motor vehicle, wherein the accessory drive system includes one or more accessory components, a motor generator of the motor vehicle, and a flexible drive element configured to transmit a torque load between the one or more accessory components and the motor generator, includes determining a maximum permissible flexible drive element torque threshold, detecting an increase in torque demand on the flexible drive element, determining when the torque demand on the flexible drive element will exceed the flexible drive element torque threshold, and reducing the torque demand of one or more of the accessory components so that the flexible drive element torque threshold is not exceeded.

A method of operating an accessory drive system for a motor vehicle, wherein the accessory drive system includes one or more accessory components, a motor generator of the motor vehicle, and a flexible drive element configured to transmit a torque load between the one or more accessory components and the motor generator, includes determining a maximum permissible flexible drive element torque threshold, detecting an increase in torque demand on the flexible drive element, determining when the torque demand on the flexible drive element will exceed the flexible drive element torque threshold, and reducing the torque demand of one or more of the accessory components so that the flexible drive element torque threshold is not exceeded.

In one variation, a pulley arrangement includes a base pulley portion rotatable within a driving plane, an adjustable pulley portion coupled to the base pulley portion wherein the adjustable pulley portion is rotatable relative to the base pulley portion within the driving plane, and a driving member including an end coupled to the adjustable pulley portion wherein at least a portion of the driving member is wrapped at least partially around the adjustable pulley portion. In another variation, a pulley arrangement includes a base pulley portion rotatable around an axis, an adjustable pulley portion coupled to the base pulley portion and movable in a first direction parallel to the axis, and a sliding block engaged with the adjustable pulley portion, wherein the sliding block moves in a second direction different from the first direction, in response to compression of the adjustable pulley portion against the base pulley portion.

A pulley device configured to support a belt of a chain tensioning idler or runner roller includes a bearing having a rotatable outer ring and a coaxial fixed inner ring and a pulley having at least one C-shaped pulley part that has an inner portion with an inner surface mounted on an outer cylindrical surface of the bearing outer ring, an outer cylindrical portion having an outer cylindrical surface configured to contact the belt or the chain, and a radial intermediate portion between axial outer ends of the inner and outer cylindrical portions and an axial outer end of the outer cylindrical portion, wherein the intermediate portion in cross section has a shape of an arc circle.