RU2492371C2 - Method of transmission gear operation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: method of transmission gear operation consisting in the fact that a permissible force is transmitted from a master link as it is rotated towards one side to a slave one via one elastic element of the latter and a rolling body, and transmission is interrupted when rotated towards the other side. If the force value does not exceed the permissible value, links are fixed relative to each other by wedging of the rolling body between one elastic element of the slave link and the master link, and if this value is exceeded, the rolling body is wedged apart, and the rolling body is exposed to the permissible force. At the same time as the rolling body is wedged, one elastic element is exposed to a different elastic element of the slave link made with alternating stiffness. The value of the permissible force is varied by variation of mutual position of elastic elements.

EFFECT: increased reliability and functional capabilities of a device.

4 cl, 5 dwg

Description

The invention relates to mechanical engineering and can be used to transfer force from the driven link to the leading both in rotational motion and in translation.

A known method of transmitting torque from a driven pulley to the leading by jamming between them a roller with a surface of friction material [A.S. USSR No. 50916, F16H 13/04, 1937 - analogue].

The disadvantages of this method are:

- limited functionality, due only to the transmission of torque, and only in one direction;

- the dependence of the transmitted torque on the frequency of rotation of the pulleys due to changes in the coefficient of friction of rolling from speed.

The prototype is a method of operation of the transmission mechanism, including transmitting the torque from the driven pulley to the leading one by jamming the roller between the pulleys, the surface of which is made of elastic friction material [A.S. USSR No. 1795201, F16H 13/04, 1993].

The disadvantages of the prototype are:

- limited functionality, due only to the transmission of torque in one direction;

- the dependence of the magnitude of the transmitted torque on the frequency of rotation of the pulleys due to changes in the rolling friction coefficient on speed;

- lack of regulation of the maximum value of the moment transmitted to the driven pulley;

- the implementation of the method only for devices using rotational motion;

- the impossibility of maintaining the permissible torque on the driven pulley after exceeding it for a short time, since the roller disengages and should somehow be returned to its original place to resume rotation of the driven pulley.

The objective of the invention is to remedy these disadvantages, namely, expanding functionality and increasing reliability.

The problem is solved in that in the method of operation of the transmission mechanism, including the transmission of the allowable force from the driven link to the leading one by means of the elastic element of one link and the rolling body, with a force value not exceeding the permissible value, the links are fixed relative to each other by jamming the rolling body between the elastic element and by another link, and if this value is exceeded, they release the fixation and act on the driven link with an allowable force.

The elastic element is composite. The elastic element is performed with variable stiffness. Fixing is also carried out during the reverse movement of the leading link. Fixation is carried out and removed during the reverse movement of the leading link.

These distinctive features allow you to achieve the following advantages compared with the prototype.

The fixing of the links relative to each other by jamming the rolling element between the elastic element and the other link with a force value that does not exceed the permissible value, improves the reliability, since the surface of the links does not rub against the rolling element during operation, as is the case in the prototype.

Removing the fixation and acting on the driven link with an allowable force when the load is exceeded on this link increases the reliability of operation, since, firstly, resistance to the load moment is preserved, due to which unpleasant consequences that can occur when the driven link is untwisted by the load moment can be avoided.

Secondly, after bringing the load moment to normal, the rotation of the driven link automatically resumes.

The execution of the elastic element composite and with variable stiffness increases the limits of regulation of the magnitude of the maximum force transmitted to the driven link, which expands the functionality.

The fixation of the links during the reverse movement of the leading link allows you to transfer force to the driven link during the reverse rotation of the leading link, which expands the functionality.

The implementation of the fixation and its removal during the reverse movement of the leading link allows you to limit the force transmitted to the driven link during reverse rotation.

The invention is illustrated by drawings.

Figure 1 shows the transmission mechanism that provides an allowable moment on the driven link when rotating in one direction and the absence of torque when rotating in the other. Figure 2 shows the transmission mechanism with a composite elastic element. Figure 3 shows the transmission mechanism with the translational movement of the links, providing an allowable force on the driven link when moving in one direction and the absence of effort when moving in the other. Figure 4 shows the transmission mechanism that provides an allowable moment on the driven link when rotating in one direction and transmitting the moment from the driving link when rotating in the other. Figure 5 shows the transmission mechanism that provides an allowable moment on the driven link when rotating in one or the other direction.

The transmission mechanism comprises a leading 1 and a driven 2 links installed with the possibility of moving one link in another, an elastic element 3 made integrally with the driven link in the form of a cantilever beam in contact with the rolling body 4, pressed by the spring 5 to its wedging surface 6 and to the leading link. Part of the elastic element can be made in the form of a ring 7.

Implement the method as follows.

When the driving link 1 rotates counterclockwise, the rolling body 4 locates on the jamming surface 6 of the elastic element 3, as a result of which the links 1 and 2 are fixed relative to each other, rotating at the same time (Fig. 1). Exceeding the permissible value by the rotation moment leads to the advancement of the rolling body along the jamming surface of the elastic element and to deformation (lifting) of the latter. After passing the entire jammed surface, the rolling body begins to rotate, the fixation of the links ceases, and they begin to rotate relative to each other. The amount of elastic deformation of element 3 determines the value of the permissible moment transmitted from the leading link 1 to the slave 2. In this case, after releasing the fixation, the moment of the permissible value continues to operate on the driven link 2. During the reverse rotation of the driving link 1, no moment is transmitted to the driven link, since the rolling body 4 leaves the jamming surface 6, overcoming the force of the spring 5, and does not impede the rotation of the driving link.

If the elastic element is made integral by putting on an elastic beam, for example, ring 7, then the magnitude of the permissible moment will also depend on the deformation force of this ring (figure 2). By varying the thickness of the rings (or by turning a ring having a variable cross-section), it is possible to vary the magnitude of the permissible moment transmitted from the master link to the follower.

In a similar way, the allowable force is transferred to the driven link during the translational movement of the links (Fig. 3).

If during rotation in the opposite direction it is required to transmit to the slave link the moment acting on the drive link, then the elastic element is made of variable stiffness (Fig. 4). When rotating in the opposite direction, the lower (according to the drawing) rolling element enters the jamming surface and, since the stiffness in this place at link 2 is very high, the rolling body is jammed and the links are fixed relative to each other, which contributes to the transmission of torque from the leading link to the driven . If the value of the specified stiffness is reduced, then when rotating in the opposite direction, the moment will be transmitted to the driven link, the value of which will be determined by the stiffness of the lower (according to the drawing) elastic element (Fig. 5). Note that for convenience of description, the jammed surfaces are spaced, however, they can be brought closer together (almost close to each other) and use one rolling body, which, depending on the direction of rotation, will roll from one surface to another.

The implementation of the invention will allow you to create a simple design transmission mechanism that allows you to limit the transmitted force from the leading link to the driven as with rotational motion, and with translational.

Claims (4)

1. The method of operation of the transmission mechanism, including transmitting the allowable force from the driving link when it rotates in one direction to the driven member through at least one elastic element of the latter and the rolling body and interrupts the transmission during rotation to the other, characterized in that when the magnitude of the force , not exceeding the permissible value, the links are fixed relative to each other by jamming the rolling body between at least one elastic element of the driven link and the driving link, and when this value is exceeded, the body is wedged to Variations and affect them on the driven link with an allowable effort. 2. The method according to claim 1, characterized in that when the rolling element is jammed, one elastic element is affected by another elastic element of the driven link. 3. The method according to claim 2, characterized in that the other elastic element is performed with variable stiffness. 4. The method according to claim 2, characterized in that the allowable force is changed by changing the relative position of the elastic elements.

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