A tensioner comprising a base having a cylindrical portion extending axially, the cylindrical portion comprising a radially outer surface and a receiving portion that is radially inward of the radially outer surface, an eccentric arm pivotally engaged with the radially outer surface, a torsion spring disposed within the radially inward receiving portion, the torsion spring applying a biasing force to the eccentric arm, and a pulley journalled to the eccentric arm.

A tensioner comprising a base having a cylindrical portion extending axially, the cylindrical portion comprising a radially outer surface and a receiving portion that is radially inward of the radially outer surface, an eccentric arm pivotally engaged with the radially outer surface, a torsion spring disposed within the radially inward receiving portion, the torsion spring applying a biasing force to the eccentric arm, and a pulley journalled to the eccentric arm.

Disclosed herein is an assembly, method of assembling, and kit for assembling an assembled flexible helical belt that is mounted within a mounting space defined by a continuous mechanical constraint of a device. Embodiments of the flexible helical belt include a flexible helical belt that has a plurality of belt teeth, where some of the belt teeth are each pierced by a through hole which extends through the respective belt tooth and where the flexible helical belt is of sufficient length such that, when the flexible helical belt is mounted within the intended mounting space, the flexible helical belt overlaps itself by at least one rotation such that each through hole is transversely aligned with at least one other through hole, enabling a transverse compression device to be fitted through the through holes, creating a transverse compressive force on the flexible helical belt to form a single continuous drive belt.

A tensioner that includes a mount, a pair of tensioner arms, and a spring. The mount defines a movement axis. Each tensioner arm assembly has a first tensioner arm, which is coupled to the mount for sliding movement about the movement axis, a tensioner pulley and a spring guide. The tensioner pulley and the spring guide are coupled to an associated tensioner arm for movement therewith. The spring is mounted on the spring guides and biases the tensioner arm assemblies about the movement axis in respective directions that urge the tensioner pulleys toward one another.

An object of the present invention is to provide a tensioner lever capable of consistently exerting appropriate reaction force to various tension fluctuations in conjunction with varying chain behavior, and reducing vibration and noise when the chain runs. The tensioner lever of the present invention includes a torsion coil spring having a pressing arm in which a distal end portion abuts on a lever body to form a first load point, and a support arm in which a distal end portion abuts on a support part provided to an attachment surface to form a first support point. The tensioner lever further includes a spring load adaption structure configured to form one or both of a second loading point and a second support point when a certain level or more of load is received from the chain.

Some embodiments provide a belt tensioning mechanism for a 3D printer and a 3D printer. In those embodiments, the belt tensioning mechanism comprises a base, a driving pulley, at least one timing pulley, a sliding block, a tensioning pulley, a spring. The base is provided with a first sliding groove. The driving pulley and the at least one timing pulley are mounted on the base and are connected in series with each other via a belt. The sliding block is mounted on the base and is capable of sliding along the first sliding groove. The tensioning pulley is mounted on the sliding block and is connected in series with the driving pulley and the at least one timing pulley via the belt so as to tension the belt. The spring is configured to apply an elastic force to the sliding block.

Various embodiments provide a timing belt tensioner for a 3D printer and the 3D printer. In those embodiments, the timing belt tensioner includes: a mounting frame, an idler and an elastic member, where the idler is connected to the mounting frame, and a timing belt of the 3D printer is wound around the idler, and is configured to drive a movement mechanism of the 3D printer to move on an XY plane; and the elastic member is configured to connect the mounting frame and a base of the 3D printer such that the mounting frame drives the idler to slide to a balance position relative to the base under an elastic force of the elastic member. When at the balance position, a balance is reached between the elastic force of the elastic member and a tensile force of the timing belt acting on the idler.

A tensioner comprising a base defining a hole, the hole having a center C, the hole having a diameter sufficient to receive a driven pulley, a rotary arm engaged with the base by a retaining member connected to the base, the rotary arm rotatable about the center C, a pivot arm mounted to the rotary arm on a pivot, the pivot offset from center C, a first pulley journalled to the rotary arm, a second pulley journalled to the pivot arm, a torsion spring engaged between the rotary arm and the pivot arm for biasing the second pulley toward the first pulley, a damping member frictionally engaged between the base and the rotary arm, and the rotary arm defining a portion for receiving a first pulley fastener whereby a first pulley position is adjustable.

A belt tensioning device comprises: a base member; a first tensioning arm, which is pivotably supported by a bearing sleeve on the base member around a first pivot axis and which comprises a first tensioning roller, wherein the bearing sleeve is configured radially elastically and is connected to one of the components, the base member and the first tensioning arm in a rotationally fixed manner, and which is rotatable relative to the other of the components, the base member and the tensioning arm a second tensioning arm, which is pivotably supported on the base member around a second pivot axis and comprises a second tensioning roller; a spring arrangement that pre-tensions the first tensioning arm and the second tensioning arm in circumferential direction relative to each other; pre-tensioning means, which that are arranged radially between a circumferential face of the bearing sleeve and a circumferential face of the component connected to the bearing sleeve to exert a radial force in direction relative to the component rotatable thereto.

An orbital tensioner comprising an annular base, a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A), a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A), a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm, a torsion spring biasing the pivot arm in a first direction, the ball bearing having a first race and a second race, the ring fixed to the first race, the annular base fixed to the second race, and a damping mechanism frictionally disposed between the ring and the base.