A belt-tensioning device includes an electric machine having a drive belt pulley, which is driven about a drive axis, and a further drive belt pulley, where an endless belt wraps around the drive belt pulleys. The device has a housing in which a first and a second spring arm are mounted, in each of which spring arms a tension roller having axes of rotation which are parallel to the drive axis is rotatably mounted. The spring arms are supported against one another and press the endless belt together via the tension rollers in the region of the drive belt pulley. A first and a second further spring arm are provided adjacent to the spring arms which are adjustable by an adjustment element such that the spring forces of the further spring arms either do or do not support the spring forces of the spring arms acting on the endless belt.

The present invention relates to a chain casing for encasing of a chain spanning a main chain sprocket and a driven chain sprocket, such as having two free chain parts, a pulling chain part and a returning chain part, of preferably a vehicle, such as a bicycle having a frame, the chain casing having: —a main chain sprocket cover element for covering of the chain at the main chain sprocket, such as a pedal spindle chain sprocket; —a pulling chain part cover element for covering of at least a part of a pulling chain part between a main chain sprocket and the driven chain sprocket; —a returning chain part cover element for covering of at least a returning chain part between the main chain sprocket and the driven chain sprocket; —a chain tensioner cover element for covering of a chain tensioner assembly with the chain arranged therethrough. Furthermore, the present invention relates to a chain tensioner assembly, preferably fitting in the chain casing.

A belt tensioning device includes a first tensioning arm mounted on a base body pivotably about a first pivot axis and includes a rotatable first tensioning roller. A second tensioning arm is pivotably mounted relative to the base body about a second pivot axis and includes a rotatable second tensioning roller. Via a spring arrangement between the first tensioning arm and the second tensioning arm, the first and second tensioning arms are resiliently supported against one another in the circumferential direction. A damping mechanism is operatively arranged between the base body and the first tensioning arm for damping relative rotational movement between the first tensioning arm and the base body. The damping mechanism generates a varying damping torque dependent on the rotational position and/or rotational direction of the first tensioning arm relative to the base body upon pivoting of the first tensioning arm relative to the base body.

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 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.

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.

A tensioner includes a base, a tension arrangement rotatable at the base, a damping member being rotated in a loading direction by the tension arrangement, and an elastic member biasing against the damping member. The position of the damping member depends by the layout geometry of the specific application and is directly in opposition to the hub load. The reaction force of the cylindrical surface of the base on the damping member is very near to the plan of the external forces represented by the hub load to minimize the deflection of the shaft. The tension arrangement is rotated to push the damping member for generating a first positive tension between the damping member and the base, and to expand the elastic member radially for generating a second positive tension between the elastic member and the damping member, so as to enhance a damping force of the tensioner.

A belt-tensioning device, in particular for an internal combustion engine, the belt-tensioning device including a bearing housing having a latching recess, a tensioning roller, a pivoting arm and a locking device. The pivoting arm is mounted on the bearing housing, the pivoting arm being under a torsion spring load. The tensioning roller being coupled to the pivoting arm. The locking device having a first latching device and a second latching device. The first latching device and the second latching device being coupled with the pivoting arm. The latching recess interacts with at least one of the first latching device and the second latching device wherein the locking device is configured in such a way that the pivoting arm can be locked by the locking device in different predefined latching positions and the pivoting arm can be pivoted with predefined freedom in an operating position.

A tensioner comprising a base having a shaft and having a radially projecting tab therefrom, a pivot arm pivotally engaged with the shaft about a pivot axis A-A, a torsion spring disposed between the base and the pivot arm, the torsion spring in a compressed state, a pulley journalled to the pivot arm, a first axial member extending from the pivot arm, the first axial member comprising a radially projecting portion adjacent to a radially receding portion, and the radially projecting portion engaging the radially projecting tab in a first pivot arm position and the radially receding portion cooperating with the radially projecting tab in a second pivot arm position.

An object of the present invention is to provide a tensioner lever that allows for reduction of the number of components and the weight, while being able to prevent vibration and noise during the running of the chain. The tensioner lever according to the present invention is configured such that a lever body rotatably supported on an attachment surface is urged to rotate toward the chain by the resilient force of a coil spring. The coil spring includes a pressing arm extending from one end of a helical part and contacting the lever body, and a support arm extending from another end of the helical part and supported by the attachment surface. The lever body includes an engagement portion configured to allow the support arm of the coil spring to be hooked thereon by resilient deformation, and to removably engage therewith by rebound resilience of the coil spring.