Zed-type belt tensioners are described that include an arm having a first end rotatable about a first axis to move a second end of the arm into engagement with a belt, a tensioner component coupled to the first end of the arm, and a supplemental force element positioned between the arm and the tensioner component. The second end of the arm while tensioning a belt experiences a hub load applied by the belt and the supplemental force element is positioned at a point to apply a force that counteracts the hub load thereby reducing cocking of the arm. Also described herein are methods of counteracting the hub load using such belt tensioners and methods of assembly of such belt tensioners.

A belt tensioner for a belt system having a compression spring internal to the tensioning arm, the tensioning arm pivotable in relation to the pivot shaft and the tensioner base. The compression spring provides an axial force against an axially slidable hub bearing, which moves to accommodate variations in spring force and/or dimensional changes.

The utility belongs to the field of the non-beam pumping unit, specifically relating to a non-beam pumping unit with a motor output shaft righting device. The non-beam pumping unit with a motor output shaft righting device comprises a base, a tower body and a drive mechanism. The base is fixedly mounted on the ground. The drive mechanism is mounted on the platform, comprising a motor, a large roller, a small roller, a belt and a counterweight device. The motor is connected with the large roller through a chain and sprockets, and one end of the belt is connected with a beam hanger and the other end hangs down after wrapping around the large roller and the small roller from the upper side and then connected with the counterweight device.

A variable transmission system for a vehicle is configured such that, when a magnitude of a hydraulic pressure detected by an hydraulic pressure sensor is a first predetermined value or more, a chord portion of a chain belt is pressed such that a raceway length of the chain belt is extended by at least a circumferential extension amount of the chain belt at the time when the magnitude of the hydraulic pressure is the first predetermined value. Hereby, it is possible to restrain the chain belt from coming off from a sheave even in a low vehicle speed range, at a low cost, without causing a fuel efficiency decrease and a driving torque decrease of the vehicle.

A vibrating apparatus includes two axles, two composite wheels, a timing belt, a multi-ridged belt and four rods. The axles are parallel to each other. Each of the axles includes two eccentric sections. The composite wheels are respectively connected to the axles. Each of the composite wheels includes a timing pulley and a multi-ridged pulley coaxially in one piece with the timing pulley. The timing belt is wound around the timing pulleys. The multi-ridged belt is wound around the multi-ridged pulley. The rods are pivotally connected to the eccentric sections of the axles.