DE19706347A1 - Main and locking nut - Google Patents

Abstract

The nuts (1,2) secure a shaft or bolt with an external thread (4). The main nut (1) is in turn secured by a locking nut (2) on the same main thread. Each nut has a drill hole which is coaxial with that of the other nut parallel to the main thread. The two nuts are interlocked by a single bolt (3) passing through both coaxial holes in the nut walls. They are pulled together with their thread flank contacts in opposing directions.

Description

State of the art

A tightened normal nut with the help of a similar counter nut against twisting securing is a well known technique.

The problem is that the clamping forces of a screwed base and that of tightened lock nut are directed against each other and thereby the effect of used main mother is more or less neutralized. As a result, they are shifting Low tension forces on the lock nut, the pressure on the pad is uncontrolled changed and the desired anti-rotation protection is not guaranteed.

A lesser known technique to secure screw connections is to lock the body Partially separate the female thread in the radial direction and the two resulting partial Tighten halves again with one screw.

The problem with this is that the restricted zone in the flanks of the main thread is asymmetrical and can only be applied in a small area. There is also a material deformation of the screw body, which is certainly for alternate use Precision machines may not be suitable. However, the limited achievable remains in use Anti-twist protection stable.

problem

The invention specified in protection claim 1 is based on the problem of a To create locking screw which, in every type of use, has the highest level of security against rotation or release of the locking mechanisms.

solution

This problem is solved with the features listed in protection claim 1. The support forces of the main nut ( 1 ) and the tensile forces of the tensioning screws ( 3 ) act in the same direction and thus the flank contact in the main thread always remains on the same side. In addition, since the main nut ( 1 ) and the counter nut ( 2 ) cannot be rotated against each other by fixing the tensioning screws ( 3 ), changing tension and angular momentum that are applied from "outside" have no influence on the locking system.

Achieved advantages

With the invention it is achieved that for many technical applications a reliable and stable locking nut system is available that with a correspondingly precise design meets the highest demands, is basically easy to use and up to the wear limit can be released and locked again as often as required.

Embodiments and application

The locking nut system is a convenient screwing unit with the corresponding Favorable dimensions and good mechanical design a maximum level of locking effect is achieved, which is to be applied to a thread at all. Both very small are conceivable Units for use in precision engineering as well as medium and unusual sizes for use in mechanical engineering in general.

As part of developing a properly functioning prototype with a Main thread M20 × 2 and three clamping screws with thread M6 have some Significant insights are drawn, which are indicated below.

• 1. Rotationally symmetrical basic shape and continuous splines ( 7 ) over the entire screwing unit for receiving socket wrench tools that reach into the main nut ( 1 ) enable very universal use and simple assembly. Two symmetrically arranged clamping screws ( 3 ) promote easy tightening according to "feeling". Three or more turnbuckles should be tightened with torque tools.
• 2. If one-time installation is planned, the clamping screws ( 3 ) can be secured using conventional means. With frequently changing use - e.g. B. Tool holders - ball or conical seats on the clamping screws ( 3 ) are ideal.
• 3. A collar ( 6 ) between the main nut ( 1 ) and lock nut ( 2 ) has a beneficial effect on maintaining the balance quality. The axial play between the two elements main nut ( 1 ) and lock nut ( 2 ) should be at least 0.5 × thread pitch and, depending on the thread type, more. The clamping screws ( 3 ) must also be fixed in this position. With exactly symmetrical arrangement of the clamping screws ( 3 ), the axial play can be easily adjusted in the grid of the clamping screw distances. The thread of the lock nut ( 2 ) is always in the correct position.
• 4. Since the counter nut ( 2 ) is not loaded when the main nut ( 1 ) is tightened - see note 1.), the thread adhesion can be further increased by deepening the flank roughness in the thread area of the counter nut ( 2 ).

Claims (3)

1. Locking nut system for applying high neutral anti-rotation forces, characterized in that the main buffer ( 1 ) and lock nut ( 2 ) on the common bolt thread ( 4 ) are tightened by means of clamping screws ( 3 ). 2. Locking nut system according to protection claim 1, characterized in that the direction of the support forces in the thread flanks of the main nut ( 1 ), which can be stretched over any base ( 5 ), is retained by the function of the lock nut ( 2 ) and the pressure in the Thread flanks of the main nut ( 1 ) is reinforced by the tension of the clamping screws ( 3 ). When locked, the system is neutral, ie external forces have no effect on the locking effect as long as the clamping screws ( 3 ) are tightened. 3. Extension to point 2 - lock nut.
By deepening the flank roughness in the threads of the lock nut ( 2 ), the adhesion in the locked state is further increased.