RU2797003C1 - Drive tensioning mechanism with reversible movement for mechanical gears of agricultural machines - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: drive tension mechanism with reverse movement for mechanical transmissions of agricultural machines contains driving and driven pulleys (2 and 3), belt (4), two tension pulleys (9 and 10) mounted on two levers (7 and 8), spring (15), two axes (13 and 14), against which two levers (7 and 8) can be rotated. The tension pulley (10) is located in the active run (5) of the belt (4), and the second pulley (9) is located in the active run (6) of the belt (4). The arm (11) of the action of the force from the spring (15) on the arm (7) with the tension pulley (9) installed in the active run (6) of the belt (4) is three times less than the arm (12) on the lever (8) with tension pulley (10) installed in the active run (5). Due to the difference in the length of the arms (11 and 12) of the action of the force from the spring (15), the active run (6) is tensioned with less force than the active run (5).

EFFECT: increased belt life and increased reliability of the reverse drive, reduced costs for maintenance of the belt drive during operation.

2 cl, 3 dwg

Description

The claimed invention relates to agricultural engineering and can be used in mechanical transmissions, including spring-loaded tensioners used to tension belts or chains in reverse motion drives.

Belt tension mechanisms are known in drives with reverse motion. Such mechanisms provide tension to the belt drive using two tension pulleys, with one tension pulley located in the leading branch and the second in the driven branch. A belt drive with a tension mechanism includes a belt, a driving and a driven pulley, two tension pulleys mounted on two levers connected by a compression spring and capable of turning around the axes fixed on the housing. Tensioning the reverse drive belt in the driving and driven branches with the same effort from the tension pulleys reduces the life of the belt and requires more frequent replacement, which leads to an increase in the cost of maintenance of the belt drive during operation [Patent DE 1575619, priority 01/15/1970].

Closest to the claimed invention is a belt tension mechanism with reverse movement [Patent WO 2000026532 A1, priority 10/29/1998], consisting of a driving and driven pulleys, a belt, two tension pulleys, one of which is located in the leading branch, and the second in the driven branch , providing belt tension, in one version, with the help of one spring, while the tension pulleys act on the belt with the same effort, in the second version, with the help of two springs, while the direction of the torque on the drive pulley can change.

The disadvantages of the prototype: in the first variant, the belt tension of the reversible drive in the driving and driven branches with the same effort from the tension pulleys reduces the resource of the belt and requires more frequent replacement, which increases the cost of maintenance of the belt drive during operation; in the second variant, in the design with two springs, it is necessary to perform work on adjusting the force of two springs, which increases the complexity of the work associated with servicing the belt drive during operation.

The purpose of the invention is to increase the resource of the belt and increase the reliability of the reverse drive, reduce the cost of maintaining the belt drive during operation.

The technical result is achieved due to the fact that the reverse drive tension mechanism, which includes the driving and driven pulleys, a belt, two tension pulleys mounted on two levers, one of the tension pulleys is located in the driving branch, and the second in the driven branch, two axis, about which two levers can be rotated, while the levers are connected by a tension or compression spring. The shoulder of the force from the spring on the lever with the tension pulley installed in the driven branch of the belt is three times less than the shoulder on the lever with the tension pulley installed in the driving branch. Due to the difference in the length of the arms of the action of the force from the spring, the driven branch is pulled with less force than the leading one. The tension mechanism can be used in chain drives, where a chain is used instead of a belt, and sprockets are used instead of pulleys.

The use of levers with arms of different lengths of the action of the force from the spring makes it possible to reduce the force from the tension pulley on the driven branch during operation, which increases the service life of the belt, increases the reliability of the reverse drive; provides adjustment of the tension force by a single spring, reduces the labor intensity of work and the costs associated with servicing the belt drive during operation.

The invention is illustrated by drawings:

fig. 1 - tension mechanism of the reverse drive with compression spring, operating mode;

fig. 2 - mechanism for tensioning the reverse drive with a compression spring, reverse mode;

fig. 3 - mechanism for tensioning the reverse drive with a tension spring.

The claimed device includes the following structural elements (figure 1 - 3): 1 - body; 2, 3 - driving and driven pulleys; 4 - belt with leading 5 and driven 6 branches; 7, 8 - levers with tension pulleys 9, 10 (asterisks) and shoulders 11, 12; 13, 14 - axes; 15 - compression spring; 16, 17 - directions of rotation of the drive pulley 2 in the operating and reverse modes of operation of the drive, respectively; 18 - extension spring.

The drive pulley 2 (see Fig.1, 2) is connected to the driven pulley 3 with a belt 4. On the housing 1 fixed axles 13 and 14, which are mounted levers 7, 8 with tension pulleys 9, 10. In this case, the lever 7 with the tension pulley 9 is installed in the driven branch 6 of the belt 4, and the lever 8 with the tension pulley 10 is installed in the leading branch 5 of the belt 4. The lever 7 includes a shoulder 11 connected by means of a compression spring 15 with the shoulder 12 from the lever 8. In the case of when the tension spring 18 is used, its ends are attached to the levers 7 and 8 (see figure 3).

The device works as follows. When the direction of rotation in the operating mode 16 or reverse mode 17, the drive pulley 2 drives the driven pulley 3 in rotation using the belt 4 (see Fig.1, 2). The tension of the belt 4 is provided due to the pressure on the driven 6 and the leading 5 branches from the tension pulleys 9, 10 mounted on the levers 7, 8, and the action of the force from the compression spring 15 on the shoulders 11 and 12 from the composition of the levers 7, 8. In this case, the levers 7, 8 are mounted on axles 13, 14, fixed on the body 1. Shoulder 11 from the lever 7 is three times smaller than the shoulder 12 from the lever 8, which provides less force on the driven branch 6 of the belt 4.

The tension of the belt 4 can also be provided by pressure on the driven 6 and the leading 5 branches from the tension pulleys 9, 10 mounted on the levers 7, 8 connected by the tension spring 18. In this case, the attachment point of the tension spring 18 on the lever 7 is located at a distance, three times smaller to the axis 13 than the point of attachment of the tension spring 18 on the lever 8. This provides less force on the driven branch 6 of the belt 4 (see figure 3).

The reversible tensioning mechanism described can be applied to a chain drive. In this case, belt 4 is replaced by chain 4 with leading 5 and driven 6 branches, and leading 2, driven 3 and tension pulleys 9, 10 are replaced by drive 2, driven 3 and tension 9, 10 sprockets.

The technical result lies in the fact that the use of levers with shoulders of action of different lengths of the force from the spring makes it possible to reduce the force from the tension pulley on the driven branch during operation, which increases the service life of the belt, increases the reliability of the reverse drive and reduces the cost of maintaining the belt drive in the process operation.

Claims (2)

1. Drive tension mechanism with reversible movement for mechanical transmissions of agricultural machines, including driving and driven pulleys, a belt, two tension pulleys mounted on two levers, a spring, two axles, relative to which two levers can be rotated, and one of the tension pulleys is located in the leading branch, and the second in the driven branch, characterized in that the shoulder of the force from the spring on the lever with the tension pulley installed in the driven branch of the belt is three times less than the shoulder on the lever with the tension pulley installed in the leading branch, at the same time, due to the difference in the length of the arms of the action of the force from the spring, the driven branch is stretched with less force than the leading one. 2. The mechanism according to claim 1, characterized in that the spring connects the two levers and is made in the form of a single extension spring or compression spring.

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