A tensioner comprising a base, a shaft press fit into the base, a pivot arm journalled to the shaft, the pivot arm having a first frustoconical portion and a frustoconical bushing disposed thereon, a pulley journalled to the pivot arm, a torsion spring engaged between the base and the pivot arm for biasing the pivot arm, a seal disposed between the base and pivot arm on the shaft, the shaft comprising a second frustoconical portion describing an apex angle Δ, and the torsion spring applying an axial spring force to the pivot arm such that the first frustoconical portion is in pressing engagement with the second frustoconical portion.

A tensioning system including a magnetic stop is provided. The tensioning system includes a tensioner arm and a support. The tensioner arm is mounted on the support for pivoting movement. The support includes a support magnetic or ferromagnetic element on at least a first surface thereof. The tensioner arm includes a tensioner arm magnet on at least a second surface thereof that faces the first surface of the support.

To provide a tensioner capable of preventing slipping between a rack portion and ratchet pawls and securing a large backlash with a simple structure. The tensioner includes a ratchet rotatably mounted on a housing and having a front pawl and a rear pawl spaced apart in a front and rear direction on a side face positioned opposite the rack portion. The ratchet includes an additional pawl formed between the front pawl and the rear pawl in the front and rear direction on the side face positioned opposite the rack portion.

To provide a tensioner capable of preventing slipping between a rack portion and ratchet pawls and securing a large backlash with a simple structure. The tensioner includes a ratchet rotatably mounted on a housing and having a front pawl and a rear pawl spaced apart in a front and rear direction on a side face positioned opposite the rack portion. The ratchet includes an additional pawl formed between the front pawl and the rear pawl in the front and rear direction on the side face positioned opposite the rack portion.

A fan apparatus may include a frame, a fan, and a drive mechanism. The fan may be supported for rotation relative to the frame and may include a fan shaft and a plurality of blades extending outward from the fan shaft. The drive mechanism may include a driven wheel, a drive shaft, a first drive wheel, a second drive wheel, and a torque-transmission loop. The driven wheel may be mounted on the fan shaft. The drive shaft may be supported for rotation relative to the frame. The first drive wheel may be mounted on the drive shaft. The second drive wheel may be mounted on the drive shaft. The torque-transmission loop may be engaged with the driven wheel and a selected one of the first and second drive wheels.

Apparatus, systems, and/or methods for adjusting belt tension in a material removal machine are disclosed. In some examples, the material removal machine includes a material removal tool secured on a spindle. A spindle pulley may be secured to the spindle, such that rotation of the spindle pulley causes the material removal tool to be rotated via the spindle. The material removal machine may further include a movable hub that retains the spindle, such that movement of the hub translated into movement of the spindle. Because the spindle pulley is securely attached to the spindle, movement of the hub may translate into movement of the spindle pulley. This movement of the spindle pulley may change a distance between the spindle pulley and an actuator pulley, thereby changing the tension in a belt connecting the spindle pulley and the actuator pulley.

An object of the present invention is to provide a chain drive system capable of reducing sliding resistance between a chain and a guide shoe, suppressing an increase, over time, in sliding resistance, and reducing wear on the guide shoe. A chain drive system according to the present invention includes a chain having a plurality of chain plates, a plurality of sprockets on which the chain is wound, and one or more guides each including, integrally or separately, a guide shoe having a chain-running surface, and slidably guiding, in presence of lubricating oil, the chain. At least one of the plurality of chain plates has a lubricant region retaining a solid lubricant.

An object of the present invention is to provide a chain drive system capable of reducing sliding resistance between a chain and a guide shoe, suppressing an increase, over time, in sliding resistance, and reducing wear on the guide shoe. A chain drive system according to the present invention includes a chain having a plurality of chain plates, a plurality of sprockets on which the chain is wound, and one or more guides each including, integrally or separately, a guide shoe having a chain-running surface, and slidably guiding, in presence of lubricating oil, the chain. At least one of the plurality of chain plates has a lubricant region retaining a solid lubricant.

A chain tensioner transmits power of a crankshaft provided in an engine to peripheral auxiliary devices and guides a chain belt that transfers engine oil. The chain tensioner includes a body portion that tensions the chain belt through a pivot, the upper surface of the body portion includes an oil guiding rib that collects the engine oil scattered from the chain belt to the upper part, one surface of the body portion in contact with the upper surface includes a pivot journal, and one surface of the body portion includes a first oil flow path that guides the engine oil to flow down to the pivot journal.

A chain tensioner transmits power of a crankshaft provided in an engine to peripheral auxiliary devices and guides a chain belt that transfers engine oil. The chain tensioner includes a body portion that tensions the chain belt through a pivot, the upper surface of the body portion includes an oil guiding rib that collects the engine oil scattered from the chain belt to the upper part, one surface of the body portion in contact with the upper surface includes a pivot journal, and one surface of the body portion includes a first oil flow path that guides the engine oil to flow down to the pivot journal.