RU2368544C1 - Device for fixation of flexible joint - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: device corresponds flexible joint with swivelling parts (1), (2). On one of them (2) it is installed locating fixture in the form of fixed on axis (4) of hook (5), spring-loaded by spring (6). Interacting with the second part (1) rigid connector (8) is installed with excentricity relative to rotation axis (3) of flexible joint. On the second detail (1) it is fixed axis (7) with ability of interaction with inner side of hook (5). Hook is implemented with angle φ between its surface (A), contacting to particular axis (7), and plane, passing through point of this contact and rotation axis (3) of flexible joint. This angle fulfil conditions φ ≤ arctgµ, where µ, - minimal friction coefficient in a place of contact of axis and hook. Hook (5) under action of spring (6) push the axis (7) and ensured by angle φ creates strain in the direction B, by means of which it is achieved selection of looseness in conjunctions of flexible joint. Backward motion of part (1) relative to part (2) and iterative initiation of looseness is excluded ensured by invariable position of hook (5) relative to axis (7) thanks to friction incipient between them.

EFFECT: reliability enhancement of check of flexible joint at slow speed of opening of rotary structures and keeping of rigidity of opened structure at action of outer loads, exceeding calculated.

1 dwg

Description

The locking device of the hinge assembly mainly relates to the locks of the deployed position of the satellite rotary structures, for example solar panels or antennas.

A device for fixing according to patent No. 2250863 is known, comprising a fixing element (made in the form of a cantilever fixed leaf spring with an opening at its free end) on one of the parts of the rotary structure, and a console-mounted rod with the possibility of interaction of its free end on the other part of the rotary structure with leaf spring hole. The parts are equipped with two stops, with the help of which they are mated in the final (working) position of the hinge assembly, while one of the stops is rigid to limit the mutual rotation of the parts during their oncoming movement, and the other spring-loaded to overcome the backlash in the joints of the hinge assembly due to forces elasticity (Prototype). The prototype isolates the hinge assembly due to the high angular velocity of rotation of the rotary structures, at which kinetic energy is accumulated sufficient to actuate the spring-loaded stop. The disadvantages of the prototype are:

- inability to fix the hinge unit at the opening speeds of the rotary structures close to zero;

- the dependence of the stiffness of the open rotary structure and the ability to eliminate backlash in the joints of the hinge assembly from external loads acting on the hinge assembly, for example, from working correction or orientation engines of the satellite. The accuracy of the calculation of these external loads depends on the rigidity of the open system, the calculation of which is very difficult, and in the case of an unaccounted increase in external loads, the rigidity of the open system decreases and, as a result, the flow rate of the working fluid of the propulsion systems is used to stabilize the position of the spacecraft;

- the high stiffness of the leaf spring leads to greater resistance to the movement of the disclosed rotary structure at the time when the cantilever-fixed rod begins to interact with the leaf spring. As a result, a decrease in the reliability of disclosure.

The tasks of creating the inventive device for fixing the hinge assembly are:

- improving the reliability of the disclosure of the hinge assembly;

- the ability to lock the hinge unit at the opening speeds of the rotary structures close to zero;

- the exclusion of backlash in the joints of the hinge node and maintaining the rigidity of the open structure when exposed to external loads that exceed the calculated.

между контактирующей поверхностью крючка и плоскостью, проходящей через точку контакта и ось вращения шарнирного узла, равным φ≤arctgµ, где µ - минимальный коэффициент трения в месте контакта.The tasks are solved due to the fact that the locking device of the hinge assembly containing the hinge, on one of the parts of the rotary structure of which there is a fixing element and a rigid stop installed with eccentricity relative to the axis of rotation of the hinge assembly, interacting with the second part, is constructed so that the fixing element made in the form of a pivotally fixed rigid hook equipped with a spring, and on the other part the axis is rigidly fixed with the possibility of interaction with the inner side of the hook, angle

between the contacting surface of the hook and the plane passing through the contact point and the axis of rotation of the hinge assembly equal to φ≤arctgµ, where µ is the minimum coefficient of friction at the contact point.

The essence of the invention is illustrated in the drawing, which shows a General view of the device in a locked position.

должен удовлетворять условию:The hinge consists of parts 1 and 2 with a common axis of rotation 3. On part 2, a hook 5 and a spring 6 of hook 5 are pivotally attached to the axis 4 (for example, a torsion spring). The axis 7 is rigidly fixed on the part 1 with the possibility of interacting with the hook 5. The parts 1 and 2 are equipped with a rigid stop 8, with the help of which they are mated in the locked position of the hinge assembly. The stop 8 can be organized by any constructive methods that ensure the oncoming movement of the rotary parts during the check-in, for example, in the form of a tide (or an adjustable element) on the part 2 and the supporting platform on the part 1. The size of the stop is chosen so as to ensure guaranteed hook hook 5 per axis 7 at the time of hinging the hinge assembly with making contact only on the surface A. The power and stiffness of the spring 6 of the hook 5 is chosen for reasons of guaranteed pressing of the hook 5 to the axis 7 on the surface A with a minimum as much as possible effort to create the smallest possible resistance to the movement of the disclosed rotary structure. The design of the spring 6 of the hook 5 can be any. Axis 7 must not rotate in part 1. Angle

must satisfy the condition:

where µ is the minimum coefficient of friction at the point of contact of the axis 7 and hook 5.

создает усилие в направлении Б, чем достигается выбор люфтов в сопряжениях шарнирного узла (между осью 4 и крючком 5, осью 4 и деталью 2, осью 3 и деталью 1, осью 3 и деталью 2). Отсутствие обратного движения детали 1 относительно детали 2 и исключение вероятности повторного возникновения люфтов в сопряжениях шарнирного узла гарантируется неизменным во времени положением крючка 5 относительно оси 7 благодаря возникающему трению между крючком 5 и осью 7. Возникающее трение будет всегда удерживать крючок 5 от перемещения относительно оси 7 при соблюдении условия (1) при внешних нагрузках как расчетных, так и превышающих расчетные и гарантировать отсутствие люфтов в сопряжениях шарнирного узла. Важным фактором является то, что это трение возникает от действия самих внешних нагрузок (а не от действия пружины крючка 6) после того, как шарнирный узел зачековался. Таким образом, жесткость раскрываемой конструкции становится независимой от жесткости упругих элементов (таких как пружина).The device operates as follows. In the opposite rotational movement of parts 1 and 2, the axis 7 interacts with the free end of the hook 5, rotates it and, moving further, contacts the surface A of the hook 5. In this case, the oncoming movement of the parts 1 and 2 is limited by the stop 8. The hook 5 presses under the action of the spring 6 on axis 7 and due to the angle

creates a force in the direction B, which is achieved by the choice of backlash in the mates of the hinge assembly (between axis 4 and hook 5, axis 4 and part 2, axis 3 and part 1, axis 3 and part 2). The absence of reverse movement of part 1 relative to part 2 and the elimination of the likelihood of re-occurrence of backlash in the joints of the hinge assembly is guaranteed by the constant position of the hook 5 relative to axis 7 due to the friction between the hook 5 and axis 7. The resulting friction will always keep the hook 5 from moving relative to axis 7 subject to condition (1) under external loads, both calculated and exceeding design, and guarantee the absence of backlash in the joints of the hinge assembly. An important factor is that this friction arises from the action of external loads themselves (and not from the action of the hook spring 6) after the hinge assembly has been checked. Thus, the stiffness of the disclosed structure becomes independent of the stiffness of the elastic elements (such as a spring).

The device for fixing the hinge assembly made in this way allows us to solve the set tasks of locking the hinge assembly in a fixed position at the opening speeds of the rotary structures close to zero, and eliminating backlash in the joints of the hinge assembly when external loads exceed the calculated ones, while the spring-loaded stop is excluded from the design , on the elastic properties of which the stiffness of the open rotary construction depends, and the reliability of the disclosure is increased due to the reduced power and stiffness hook ruins compared to the leaf spring in the prototype.

This device is tested on a prototype at JSC ISS. The test results indicate the achievement of the objectives.

Claims (1)

The locking device of the hinge assembly, mainly the rotary parts of the spacecraft structures having a hinge, comprising a fixing element and a fixed stop mounted on one of the rotary parts of the hinge assembly with an eccentricity relative to the axis of rotation of the hinge assembly and interacting with the second part, characterized in that the fixing element is made in the form of a pivotally fixed rigid hook equipped with a spring, and on the second part an axis is fixed with the possibility of interaction with the inner side the hook, and the hook is made with an angle φ between its contacting surface and the plane passing through the point of contact with this axis and the axis of rotation of the hinge assembly satisfying the condition φ≤arctgµ, where µ is the minimum coefficient of friction at the point of contact of the axis and the hook.