A dynamic belt-tensioning apparatus for a treadmill includes a base having a first end and a second end spaced from the first end. A foot-striking platform is movably supported by the base so as to allow for vertical movement of the platform during operation of the treadmill. A drive belt has a fixed circumference and is positioned above a top portion of the platform. A drive roller is pivotally mounted adjacent to the first end of the base and engages the drive belt. A bell crank is pivotally coupled to the platform such that pivoting of the bell crank translates into movement of a tensioning roller that is pivotally mounted to the base and that is capable of a range of movement to provide substantially constant tension to the drive belt in response to vertical movement of the platform.

Described is a power system having an engine, a generator, a belt-driven component, a first pulley, a second pulley, a third pulley, and a fourth pulley. The engine outputs a rotational force at a first rotational speed to rotate the first pulley. The generator converts mechanical power driving the generator shaft to electric power. The second pulley is drivingly coupled to the first pulley via a first belt and configured to rotate the generator shaft at a second rotational speed based on the first rotational speed. The fourth pulley coupled to the generator shaft having a first diameter that is greater than a second diameter of the second pulley. The fourth pulley configured to drive the third pulley at a third rotational speed to drive the belt-driven component

A vehicle includes an engine having a crankshaft, an electric machine having a shaft, and a front end accessory drive (FEAD). The FEAD includes a multi-speed pulley assembly mounted to one of the crankshaft and the shaft, a pulley mounted to the other of the crankshaft and the shaft, and a tension member trained around the multi-speed pulley assembly and the pulley. The multi-speed pulley assembly is configured to establish a low speed ratio between the shaft and the crankshaft and a high speed ratio between the shaft and the crankshaft. A vehicle controller is programmed to, in switch between the high speed ratio and the low speed ratio to optimize operating conditions of the FEAD.

Power systems having reduced operating noise and associated methods are disclosed. An example power system includes an engine, a generator, a driveshaft, and a pulley system. The driveshaft may include at least one coupler configured to dampen vibration transferred by the driveshaft. The pulley system may include a first pulley and a second pulley that are drivingly coupled to one another via one or more belts. The generator may be configured to generate electric power using a rotational force received form the engine via the driveshaft and pulley system.

A utility vehicle includes a plurality of ground-engaging members, a frame supported by the ground-engaging members, a powertrain assembly supported by the frame which includes an engine, an alternator coupled to the engine through a housing, and a heating, ventilation, and air condition (“HVAC”) assembly including a compressor operably coupled to the engine. The compressor is supported on a first side of the housing plate and the alternator is supported on a second side of the housing.

A two-speed pulley assembly for an engine accessory drive includes a planetary gear, a pulley, a friction clutch, and a one-way clutch. The planetary gear has a ring gear, a sun gear, a planet carrier, and a planet gear. The planet gear is rotatable relative to the planet carrier and is drivingly engaged with the ring gear and the sun gear. The pulley circumscribes the ring gear and is in driving engagement with the ring gear. The friction clutch is arranged to selectively prevent rotation of the sun gear. The one-way clutch is arranged between the sun gear and the ring gear to permit rotation of the sun gear relative to the ring gear in a first rotational direction, and prevents rotation in a second rotational direction, opposite the first rotational direction.

A vehicle includes an engine having a crankshaft, an electric machine having a shaft, and a front end accessory drive (FEAD). The FEAD includes a multi-speed pulley assembly mounted to one of the crankshaft and the shaft, a pulley mounted to the other of the crankshaft and the shaft, and a tension member trained around the multi-speed pulley assembly and the pulley. The multi-speed pulley assembly is configured to establish a low speed ratio between the shaft and the crankshaft and a high speed ratio between the shaft and the crankshaft. A vehicle controller is programmed to, in switch between the high speed ratio and the low speed ratio to optimize operating conditions of the FEAD.

A vehicle has an internal combustion engine, an accessory, and a system having first and second belts extending between a drive assembly rotatably connected to a crankshaft of the engine and a driven assembly rotatably connected to a driveshaft of the accessory. One of the drive and driven assemblies comprises a mechanism with a shaft supporting first and second pulleys, with the first and second pulleys associated with the first and second belts, respectively. The first pulley is selectively engaged with the shaft in response to an engine speed being below a threshold value, and the second pulley is selectively engaged with the shaft in response to the engine speed being above the threshold value.

A clutched pulley assembly mountable to the shaft of a motor-generator unit (MGU) has a first sheave, with first spline teeth, rotatably mounted to the MGU shaft, and a second sheave, with second spline teeth, fixed to the MGU shaft. A slider gear with slider gear spline teeth is axially moveable between a torque transfer position, where the slider gear spline teeth simultaneously intermesh with the spline teeth of the first and second sheaves to operatively connect the sheaves to each other, and a torque cut-off position, where the slider gear spline teeth intermesh with the second sheave spline teeth but not the first sheave spline teeth so as to operatively disconnect the sheaves. An actuator drives the slider gear between the torque transfer and cut-off positions. The pulley assembly can be used in a stand-cooling mode wherein the engine is stopped but the MGU powers a load.

A system and method are provided for integrated electrification of vehicle accessories conventionally driven by an internal combustion engine in which an electric motor is coupled to a common accessory drive that drive a plurality of accessories, such as a power steering pump, an air conditioning compressor, an air compressor, a thermodynamic heater and/or a coolant pump. The integrated electrified accessory unit preferably has the electric motor, accessory drive and accessories arranged in a common housing which is configured to be mounted to a chassis frame rail of the vehicle, the common housing including wall penetrations which facilitate rapid connection of the accessories to external lines of the vehicle.