SU1631213A1 - Automatic tensioning device - Google Patents

Abstract

The invention relates to mechanical engineering and can be used in reversing transmissions with flexible coupling. The purpose of the invention is to enhance the functionality and increase maintainability. To do this, two stops are made in the device lid 2, one of which is designed to limit the angular movement of the eccentric 4 carrying the tensioning element 6 on the finger after first pressing the spring 7 when assembling the device, the other to limit the angular movement of the eccentric 4 from the working force branches of the flexible element. 3 il.

Description

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The invention relates to mechanical engineering and can be used in reversing transmissions with a flexible coupling for transmitting torque bypassing obstacles and with inter-center distance varying in operation.

The aim of the invention is to enhance the functionality and increase maintainability.

FIG. 1 shows a general view of the device in section; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows an example of using the device in transmissions with a flexible coupling with varying center-to-center distance.

The automatic tensioning device comprises a housing 1, a lid 2 in which the axis 3 is fixedly mounted. The lid 2 is fixedly mounted on the housing 1. On the axis 3 an eccentric 4 is freely mounted, made in the form of a cup with an eccentric finger 5, on which the tensioning device is freely mounted element 6. The eccentric 4 is associated with a fixed axis 3 by a torsion spring 7 (it can also be a spiral spring made of flat steel), closed by a plug 8 with fixation by a retaining ring 9.

Cap 2 is an eccentric locking element. The cover 2 has two stops 10 and 11, the stop 10 limits the angular movement of the eccentric 4 after preloading the spring 7 during assembly, and the stop 11 limits the angular movement of the eccentric 4 from the force of the working branch of the flexible element.

On the kinematic diagram (Fig. 3), the leading sprocket 12 is conventionally shown, the asterisk 13 is driven, two lower tension elements 6 and two upper tension elements 6, i.e. this diagram shows a transmission with a flexible organ using, for example, four tension 6. An obstacle, such as a wall, a branch of a receiving conveyor, etc., is indicated by the pos. 14.

The device works as follows.

When the leading sprocket 12 rotates clockwise (Fig. 3), the upper branch of the transmission, which is working, turns the eccentric 4 with the tensioning element 6, overcoming the resistance of the spring 7 (the elastic force of the spring 7 must be less than the force created by the working branch of the transmission) until it touches the eccentric planted finger 5 with the stop 11 and holds the eccentric in this position, as if fixing it. The upper tensioning elements 6 with the fingers 5, pressed against the stop 11, become stationary and act as deflecting units. The upper tensioning elements 6, located on the idle branch, automatically tension it with the elastic force of their springs. When the center-to-distance distance changes during operation, when the driven (and / or leading) sprocket moves upwards, the difference is compensated by the lower tensioning elements 6 due to the additional angular movement of the eccentric 4, and when the sprocket moves downward - under the action of the elastic force of spring 7. The connection between the lugs 10 and 11 is calculated on the basis of an increase in center-to-center distance and chain wear during operation.

By changing the direction of rotation of the drive sprocket 12 (dotted arrow

5 in FIG. 3) in reverse gears, the role of the upper and lower tensioning elements changes. In this case, the lower branch of the transmission becomes working, and the upper idler, and therefore the lower tensioning elements turn into stationary deviating blocks, and the upper tensioning elements automatically tension the idling branch of the transmission and compensate for the change in the center-to-center distance.

Claims (1)

Invention Formula An automatic tensioning device, comprising a housing, a fixed axis associated with it, mounted on the latter with the possibility of rotation and spring loaded to an eccentric carrier bearing a finger with a tensioning element mounted on it, and an eccentric locking element, characterized in that, in order to expand its functionality and maintainability, the locking element has Two stops for interacting with a finger, and an eccentric - a cap, freely mounted on the axis. FIG. 2 12