192 clutches and power-stop control – Stop mechanism – Limit stop
Patent
1997-07-03
1998-11-24
Lorence, Richard M.
192 clutches and power-stop control
Stop mechanism
Limit stop
192150, F16P 500, B64C 1328
Patent
active
058395628
DESCRIPTION:
BRIEF SUMMARY
The invention concerns a linear drive for displacing a component, in particular an aircraft wing component, according to the type defined in more detail in the preamble of claim 1.
Linear drives, by which traction and/or pressure forces are linearly transmitted, are used in various fields. A possible field of use is for aircraft wing components which, when starting or landing, for example, are moved in order to enlarge the lift at low speeds and which enlarge the surface of the hydrofoil and also change the aerodynamics. Crank drives or linear drives are used for driving said wing components such as wing flaps. If a blockage now appears in the guide of a wing component, extremely strong forces are generated which have to be absorbed in the structure of the aircraft. Since the dimension of the aircraft structure is determined by the maximum possible force, the weight also increases therewith.
In designs known in the practice, the force introduced is indirectly limited by limiting the torque of the power train. But the disadvantage of said limitation is that the force amounts to more than double the required value due to the kinetics and also to the dispersions of efficiency.
In WO 90/09921 a driving device having a variable torque-limitation system is described. But it is disadvantageous here that in this already known solution the limitation is relatively inaccurate or distinct dispersions can occur. In addition, the device is relatively dead weight.
Also known in the practice is the limitation of force devices or members in the power flow which are ruined when a predetermined force is exceeded thus constituting a sort of predetermined breakage point. But it is, at the same time, a disadvantage that the transmission of force is terminated therewith and the part must accordingly be repaired before being used again.
Therefore, this invention is based on the problem of providing a linear drive of the kind mentioned above where the force limitation occurs without ruining a structural part and where no disadvantageous weight increase occurs or the structure must be strengthened.
According to the invention, this problem is solved by the steps mentioned in the characteristic part of claim 1.
In normal operation the force is transmitted from the freewheel outer part, via the clamping members, to the inner part and then, via the spring assembly, on to the output part. When a predetermined adjusted value is exceeded, the spring assembly is compressed so that a relative movement occurs, between the freewheel outer part and the output part, which produces an uncoupling of the clamping members. An intended and precise uncoupling of the force transmission is obtained by this device without ruining a structural part.
By an adequate design of the linear freewheel provided in this manner, it can act in both directions, that is, a force limitation can be produced both in traction and in pressure.
Advantageous additional designs and developments of the invention can be seen from the sub-claims and the embodiments that, in principle, are described herebelow with the aid of the drawings. In the drawings:
FIG. 1 is a longitudinal section through the linear drive according to the invention;
FIG. 2 is a cross-section through the freewheel cage along line II--II of FIG. 1;
FIG. 3 is the same section of the linear drive according to FIG. 1 at the start of actuation;
FIG. 4 is the same section of the linear drive according to FIG. 1 at a maximum run-in position;
FIG. 5 is the linear drive of FIG. 1 at a maximum full position; and
FIG. 6 is a longitudinal section through a linear drive having two spring assemblies.
The linear drive has an input part 1, a freewheel outer part 2, a freewheel inner part 3 and an output part 4 connected therewith. Between the freewheel outer part 2 and the freewheel inner part 3 is a tubular freewheel cage 5. The freewheel cage 5 is provided with a plurality of pockets 6 in each of which are housed two clamping members, in the form of spherical rollers 7A and 7B, which are prestressed by a clamping membe
REFERENCES:
patent: 3215383 (1965-11-01), Wright
patent: 3667575 (1972-06-01), Bouhot
patent: 4176733 (1979-12-01), Twickler
patent: 4625843 (1986-12-01), Maltby et al.
patent: 5199538 (1993-04-01), Fischer et al.
Lorence Richard M.
ZF Friedrichshafen AG
LandOfFree
Linear drive for displacing a component, in particular an aircra does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Linear drive for displacing a component, in particular an aircra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Linear drive for displacing a component, in particular an aircra will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1694690