Pulley

About: Pulley is a research topic. Over the lifetime, 51636 publications have been published within this topic receiving 178220 citations. The topic is also known as: drum & block.

Effects of deformation in the dynamics of belt drive

Abstract: The dynamics of a belt drive is considered in the framework of a nonlinear model of an extensible elastic string. Under the assumption of contour motion, in which the trajectories of particles of the string are pre-determined, we transform the general equations of string dynamics to the spatial description. Further simplification regarding the absence of slip of the belt on the surface of the pulleys leads to a new model with a discontinuous velocity field and concentrated contact forces. It is shown how the computed parameters of steady operation of the drive are influenced by the chosen strain measure for the string, and differences in the behavior of synchronous and friction belt drives are pointed out. For a sample set-up, we study the dependence of the maximal transmitted moment on the angular velocities of the pulleys and on the pre-tension of the belt.

Belt stretching mechanism

Abstract: A belt stretching mechanism to adjust the tension in a belt wound around pulleys by turning an adjust bolt and moving a slider which is fastened together with a stay to an adjust bar by means of a stay-fastening bolt, wherein the axis of the adjust bolt and the axis of the stay-fastening bolt are in the same plane, so that no bending moment acts on the adjust bolt and smooth tensioning of V-belt is ensured.

Safety descender for a rope

Abstract: The descender comprises a first flange for support of a pulley and a pad, and an auxiliary braking lever mounted with limited pivoting near the pulley between an inactive unlocking position for a first winding direction of the rope in the passage space, and an active locking position in which a jamming surface of the lever presses the rope against the pulley Pivoting of the lever to the active position takes place automatically in case of incorrect winding of the rope according to a second direction opposite to the first direction, and in the presence of a tension on the rope when the descender is on load

Sliding door opening cable system with cable slack take-up

Abstract: A van door slidable in tracks (16, 18 and 20). An operating module is mounted inside the van adjacent center track 18. A front cable attached to drive pulley (144) extends through guide assembly (54) to hinge and roller assemble (26). A rear cable attached to drive pulley (136) extends through guide assembly (56) to hinge and roller assembly (26). The drive pulleys (136 and 144) each have a large diameter spiral cable groove (164), a small diameter cable groove (208) and a transition cable groove (210). A motor rotates the drive pulleys. The small diameter cable grooves drive the door when the door is in the forward portion of the tracks. The large diameter spiral cable grooves drive the door when the door is in the center and rear portions of the track. Fixed idler rollers (226 and 254) are positioned relative to the cable drive pulleys to insure that the total cable in the continuous cable loop is substantially the same when the cable is driven by the small diameter cable grooves as when the cable is driven by the large diameter spiral cable grooves. A cable tension system (220) maintains cable tension. A slack cable take-up pulley (174) on the drive pulley (136) is locked in position by teeth (194) thereon and arcuate tooth rack (172) which move into engagement by rotation of the drive pulley (144) relative to drive pulley (136).