Falling preventing device of door rolling machine

Abstract

The invention provides a falling preventing device of a door rolling machine. The falling preventing device comprises a base. A concave cavity is arranged on the base, and a self-locking gear is mounted in the cavity and is fixedly connected with a transmission shaft; movable steel balls or steel columns are arranged among teeth of the self-locking gear, ball grooves are formed in the inner side wall of the cavity, self-locking bosses are arranged on the tops of the ball grooves, the teeth are provided with arc-shaped tops, the ball grooves comprise ball groove side arcs and ball groove bottom arcs, the ball groove side arcs of each ball groove are positioned on two sides of the ball groove, the ball groove bottom arc of each ball groove is positioned at the bottom of the ball groove, and the radiuses of the ball groove bottom arcs are smaller than those of the ball groove side arcs, so that the widths of side openings of the teeth and gaps among the tops of the teeth can be gradually enlarged when the teeth approach the self-locking bosses. The falling preventing device has the advantages that the unique ball grooves are designed, accordingly, the impact strength can be reduced, the steel balls or steel columns can rub with top arcs of the teeth and the inner walls of the ball grooves after being tossed out of bottom arcs of the teeth if chains are suddenly broken under the condition of high-speed rotation of the transmission shaft, frictional force can be increased when the teeth get close to the self-locking bosses, damping and decelerating effects can be realized, and the impact strength among the teeth, the steel balls or steel columns and the self-locking bosses can be reduced.

Description

technical field [0001] The invention relates to a safety device of a rolling door machine, in particular to an overspeed self-locking safety device used in the rolling door machine to prevent chains from breaking accidentally. Background technique [0002] At present, the principle of the anti-broken chain safety device on various types of rolling door machines produced in China is: relying on the head of the brake fork installed on the end plate to withstand the tooth root of the large transmission sprocket, thereby stopping the movement of the rolling door sheet. slide. This structure has very strict requirements on the processing and installation of parts, because there are angle requirements, and a slight deviation will not have a safety effect. Therefore, this device often fails and causes frequent safety accidents. [0003] Chinese patent document 201110071346.7, Publication No. CN102168519A describes an overspeed self-locking safety device, the transmission shaft is...

AI Technical Summary

Problems solved by technology

However, this structure also has new technical problems. The number of teeth of the self-locking wheel is too large, the impact resistance is weak, and there is a situation that it cannot be locked when impacted; the hardness of the gear is too high, and the steel ball is easily broken when impacted; Finally, because the tooth was broken and stuck in the middle of the self-locking wheel, it could not continue to rotate, and the device had to be removed from the rotating shaft for replacement. The rolling shutter door was always suspended in mid-air, and the operation was very troublesome.

Images