A method of fabricating a chain tensioner includes bending a sheet metal blank to form a connector portion perpendicular to a flat base. The connector portion has an arm extending beyond the base. The method further includes stamping an end of the arm to curl the end into a hollow cylinder having an axis perpendicular the flat base. Curling the end into a hollow cylinder may be performed in a series of stamping operations. The blank may define a gap which extends around a narrower portion of the arm after the end is curled into the hollow cylinder.

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.

A chain guide is provided that can improve the work efficiency during assembly and transportability with a simple structure. The chain guide includes a bushing structure where a bushing member is attached to a guide body at least in one location. The guide body includes a cylindrical insertion hole through which a bushing cylindrical part is inserted, and a backside restricting part that restricts movement of a flange part to the back side in the guide width direction. The guide body is provided, in each bushing structure, with a front-side restricting portion that restricts movement of the flange part to the front side in the guide width direction only in one location on the outer circumference of the cylindrical insertion hole when viewed in the guide width direction.

A chain guide is provided that can improve the work efficiency during assembly and transportability with a simple structure. The chain guide includes a bushing structure where a bushing member is attached to a guide body at least in one location. The guide body includes a cylindrical insertion hole through which a bushing cylindrical part is inserted, and a backside restricting part that restricts movement of a flange part to the back side in the guide width direction. The guide body is provided, in each bushing structure, with a front-side restricting portion that restricts movement of the flange part to the front side in the guide width direction only in one location on the outer circumference of the cylindrical insertion hole when viewed in the guide width direction.

A work machine having a belt tensioning system is described. A belt is engaged with an engine drive sheave and a driven sheave of a rotor having a plurality of cutting tools configured for reducing wood infeed material. An idler pulley is mounted to an idler arm that is hinged to the machine frame. An actuator is hinged to the idler arm and the frame. The actuator may be extended and retracted in order to press the idler pulley into stronger and weaker engagement with the belt in order to set the desired amount of tension in the belt. One or more sensors may be used to sense the amount of tension in the belt, and the one or more sensors may be in communication with a control system that controls the actuator to monitor and adjust the belt tension so that it is maintained within desired limits.

Systems are provided for a belt tensioner. In one example, the belt tensioner comprises a fluid chamber divided into a first portion and a second portion via a dividing wall. An eccentric housing, which defines the fluid chamber, rotates relative to the dividing wall based on a spring force and a belt force.

A tensioner comprising a base, a ring engaged with the base, the ring rotatable about a center “C” within a base opening, a pulley journalled to the ring, a pivot arm pivotally engaged with the ring, a pulley journalled to the pivot arm, a torsion spring disposed between the ring and the pivot arm for urging the pivot arm, a damping assembly frictionally disposed between the base and the ring, a spring applying a normal load to the damping material, and the damping material having a resistance in the range of greater than 0Ω up to approximately 10,000Ω.

A chain guide and tensioning apparatus is disclosed that is configured for engagement (contact) with a driven chain (e.g., in an automotive engine). The chain guide and tensioning apparatus includes a guide body and a guide face overlying the guide body. The guide face defines an inner surface and an opposite outer surface that is configured to guide and tension the driven chain. The guide face includes a plurality of spacers that extend therefrom into engagement (contact) with the guide body so as to define at least one channel that is configured to facilitate air and/or lubricant circulation between the guide body and the guide face to reduce heat and friction generated by engagement of the driven chain with the guide face.

A chain guide and tensioning apparatus is disclosed that is configured for engagement (contact) with a driven chain (e.g., in an automotive engine). The chain guide and tensioning apparatus includes a guide body and a guide face overlying the guide body. The guide face defines an inner surface and an opposite outer surface that is configured to guide and tension the driven chain. The guide face includes a plurality of spacers that extend therefrom into engagement (contact) with the guide body so as to define at least one channel that is configured to facilitate air and/or lubricant circulation between the guide body and the guide face to reduce heat and friction generated by engagement of the driven chain with the guide face.

Two-arm tensioner for an accessory drive of an internal combustion engine, including a first arm and a second arm rigidly connected to each other and rotating around a common rotation axis (A), a first pulley connected to the first arm and rotatable around its own first axis (C), a second pulley connected to the second arm and rotatable around its own second axis (E), in which the first pulley is carried by a working arm linked to the first arm and rotatable with respect to it around a third axis (B) distinct from the first axis (D), and an elastic element configured to exert on the working arm an elastic force tending to bring the first pulley closer to the second pulley, the third axis being inside the first pulley.