|Title of Invention||
SPRING COMPONENT AND SUPPORT BEARING FOR HELICOPTER TAIL ROTOR AND CARRYING STRUCTURE FOR INPUT OUTER SPACE
|Abstract||This invention relates to a spring component for support bearing, of helicopter tail rotors or for support structures for use in outer space encompasses at least two contact support components (11a, 11b) for connecting with the members that are to be supported (e.g. a belt and a control sleeve of a helicopter tail rotor), as well as a web. plate (20), which extends between the contact support components (11a, 11b) and which includes a pair of lengthwise webs (21a, 21b) extending in a longitudinal direction. The lengthwise webs are connected to each other by first connecting webs (22a, 226), Respectively, a further connecting web (23a, 23b) is arranged at a section of the two lengthwise webs (21a, 21b) positioned between the first connecting webs (22a, 22b), wherein each further connecting web extends outwardly toward one of the support components (11a, 11b). In connection with a transverse bending moment acting on the spring component, a twisting of the lengthwise webs (21a, 21b) takes place. The spring component is flexible for transverse bending and comprises a high supporting force. A support bearing for a helicopter tail rotor or a support structure for use in outer space encompasses two or more of the spring components. In a control sleeve bearing of a helicopter tail rotor the belt is held in the control sleeve between two oppositely positioned spring components.|
|Full Text||-1A -
Spring component and support bearing for helicopter tail rotor and carrying structure for input in outer space.
The present invention refers to a spring component for support bearing, particularly helicopter tail rotors, as also a support bearing for a helicopter tail rotor or for a carrying structure for input in outer space.
Support bearing with elastic components are used specially in construction of helicopter rotors. Bearingless tail rotors of helicopters comprise essentially of belts v/hich are fastened to the rotor mast with a few bolts. The belts run inside of rotor blades, whose ends show on the side of rotor mast a control bag. The torsion of rotor blades required for control is attained through a torsion of control bag. The belts provide tail rotor the required strength and they are elongated thr- • ough the centrifugal force and bending moment appearing during the rotation. By a torsion of a rotor blade over the control bag a twist of belt of about 25 takes place. Therein a relative torsion between the control bag and the belt must be guaranteed and at the same time the bag must be supported in transverse direction that means in strike direction of rotor. The joint between the belt and the control bag is produced through a support bearing, through which the belt is held in the control bag. Through the strong centrifugal -and bending forces, which appear at this location of rotor, the support bearings are exposed to high load. Usually elastomer bearings are used as support bearing, whose support components are made out of layers of Titanium - or Steel plates, between which always an elastic material, for example rubber is located. The belt is held in the middle of control bag between oppositely lying elastomer bearing components. On ground of strong loads, for such type of elastomer bag support bearing special materials are used and they must display moreover a special structure
to withstand the load. These known elastomer bearings are therefore extremely costly, since they require a cost intensive development and manufacture. Moreover they show the disadvantage, that they change their rigidity and their material property at different temperature. The results are a reduced service life on ground of additional emerging stresses.
To reduce manufacturing cost in the serial production of helicopter tail rotors, it was tried in new developments to substitute elastomer bearing through twistable supports. Such a concept is described in "DEVELOPMENT OF BEARINGLESS TAIL ROTORS", Huber et. el. Two day International Conference on Helicopter Yaw Control Concepts, 28.February, 1990,London. In such support components, at a relative twisting of belt however likewise a vary high additional stresses appear in the support component, which leads to premature material fatigue and increased cracking danger.
The service life of conventional support bearing in area of helicopter tail rotor is thus limited and only through expensive material composition can be held in a reasonable range.
It is therefore the assignment of present invention, to
overcome the above mentioned disadvantages and to create a sp
ring component for support bearing and a support bearing for
helicopter tail rotors and carrying structures, in which the
manufacturing costs are reduced and a secure and durable, mov
ing storage of components at higher support strength is guaran
The spring component as per invention covers : at least
two support components for connection with propping components; one webplate, which connects the support component over
wherein in the webplate, a pair of linear webs running ,in longitudinal direction is formed, which are combined through first connecting web running in direction of width. and wherein to a section laid between the first connecting webs
3 atleast one lisear web that means in an area of linear webs, whice lies between the lugs of further connecting webs at linear web. a further connecting web is arranged, which stretches towards outside in direction of one of the support components, so that in a transverse bending moment acting on the spring component a twisting of linear web takes place.
Advantageously both the linear webs are connected at their ends with each other through a first connecting web, wherein the further connecting web, preferably is arranged at a central section, or rather in the middle of respective linear web. Through it a rectangular web frame between support components for admission of forces over the further connecting webs is built. The further connecting web can stretch up to support component and build the combination to support component or it can be combined with a further linear web, which then preferably builds the combination to support component. In this case, it gives a special firm combination between the web plate and the bordering support component, preferably over the entire length of further linear web.
Advantageously the web plate has essentially a rectangular form, wherein preferably the mutual distance of components is determined through the width of web plate and wherein particularly the linear web and the connecting web are formed through at least one slot in the web plate running in longitudinal direction. Through it, in a simple way a single piece web plate can be formed through which the crack danger and also the costs are reduced since they are produced in a simple and rational way. Advantageously the further connecting web is built through two slots which run one above the from the free borders of
Preferably the support components have the bearing
areas which show opposite directions wherein the web plate is arranged vertical to the bearing area. Through here the appearing forces can be absorbed by the bearing areas and the web plates in advantageous way and it provides a specially high support force in area of spring component. The bearing areas or rather support components can be combined with propping components through clamping, adhesion or bolting. In the support components or rather bearing areas for the components, preferably one or more expansion joints are arranged, which run preferably in
transverse direction. Through it, different heat expansions of spring components opposite to components with which it is combined are equalised.
Preferably the length L of linear web is so chosen that the spring component has the desired transverse bending strength and the breadth b of connecting web and the height h of linear web can be so chosen, that the spring element has the desired expansion rigidity. Consequently the elastic properties of spring elements can be adjusted through suitable selection of size of different webs. Therein the breadth b of connecting web is preferably about 1/15 to 1/5 of length 1 of linear web, particularly preferred about 1/8 to 1/4 and specially preferred about 1/3 of length of linear web. The spring element is preferably nanufactured out of a fibre compound material, through which a very high support strength and advantageous material properties at a spacially easy construction way and reduced cost can be achieved.
According to a further aspect of invention, a support bearing is created which covers a spring component as per invention. In the support bearing as per invention, two or more spring components are arranged such that they with their support components lie opposite to each other to hold a component in between, so that the component is rested swivelling. Therein the component can be a belt of a helicopter tail rotor, which through spring elements is rested in bag bearing. With such a support bearing as per invention a high support force for holding or positioning of belt' in the control bag is achieved, wherein the belt can be twisted in longitudinal direction against the support bearing. Specially the manufacturing costs are reduced inspite of high stability, stabler storage and longer service life. In the support bearing as per invention, the spring components can also tie a sensitive structure with a support frame, preferably at three points. Through it a specially light structure with reduced strength, which otherwise was exposed to large crack danger can be stored attenuated and can be stabilised. Therein the support frames, can be for example a carrying structure for input in outer space and the sensitive structure can be a flat structure like for example a space
mirror or a solar panel.
In following preferred execution forms of invention are described as for example with help of diagrams in which Fig.1. is a schematic view of a bearingless four blades tail rotor, in which the spring component as per invention can be input.
Pig.2a is a part section view of a known four blades tail rotor which possesses a known elastomer-bag support bearing. Fig.2b. is a plan view of the four blades tail rotor shown in Pig. 2a.
Fig.3. represents schematically a cross section along the line A - A' through the four blades tail rotor shown in Fig.2b, in area of known elastomer bag bearing.
Fig.4. shows a cross section through a further known elastomer bag support bearing with an arrangement of elastomer bearing components.
Fig.5a shows a first preferred execution form of spring component as per invention.
Fig. 5b is a front view of first preferred execution form of spring component as per invention.
Pig. 5c is a side view of first preferred execution form of spring component as per invention.
Fig. 6 shows schematically a cross section through a support bearing of a helicopter tail rotor.
Fig. 7a is a front view of a support bearing as per invention through which a tail rotor belt is positioned in a control bay. Fig. 7b is a side view of support bearing shown in 7a. Fig. 8a shows a further execution form of spring component as per invention.
Fig. 8b is a front view of spring component shown in Fig. 8a Fig. 8c is a side view of spring component shown in Fig. 8a; and Fig. 9 is a representation of a space mirror which is combined
with a carrying structure.
In figure 1 a typical bearing less four blades tail rotors, is
represented which is usually equipped with an elastomer- bag bearing
and as per present invention is equipped with support bearing and
spring components as per invention. The tail rotor shows four rotor
blades 1, each of which is combined with rotor mast 3 over a control bag 2. In inside of rotor blades 1 the through going belts are located, which admit the centrifugal and bending forces.
Fig. 2a. shows a part section through a known four blade tail rotor. Within the rotop blade 1 and control bag 2, the belt 4 is held through a known elastomer bag support bearing 5. In a torsion of control bag 2 the belt 4 remains in area of rotor mast 3 in it's length unchanged, while it is twisted in area of control bag 2 and rotor blade 1. Therein a twist of belt 4 of upto 25o against it's position in area of rotor mast 3 can take place.
Fig. 2b. shows a plan view on the known arrangement. The control bags 2 are each twisted through blade lever 6, which over the control bar, which put on control bar bearing 7, are operated. The belt 4 represented through the dotted lines runs through going through each of two oppositely lying rotor blades 1 and is propped in the area of control bag 2 in it's middle through the elastomer - bag bearing 5. The cross section through the known control bag along the line A- A' is schematically represented in Fig. 3.
A further known arrangement of known elastomer bearing component in a support bearing is represented in Fig.4. Therein the belt 4 is held on it's both sides through the known elastomer components in centre of control bag. To withstand high loads, these known elstomers bearing are built of layers of Titanium or steel plates, between which in each case a layer of rubber is located. The disadvantages of this known bearing assembly were discussed
The Fig. 5a to 5c showa first preferred execution form
of spring component as per invention, which as per present invention in place of known elastomer bearing components is input in the control bags 2 of previously shown helicopter tail rotor, to store or rather hold the belt 4. The spring component 8 has in it's central part a support plate or rather web plate 20 which are planned for absorption of forces between two components distanced from each other, in order to prop the components mutually or rather to keep their distance in area of
web plate 20 constant. Therein the breadth B of web plates 20 determines the distance between the components.In longitudinal direction the web plate has the length 1 so that it in built in condition stretches between the components to be propped in longitudinal direction. It is to be seen from Fig. 5c that the web plate has a rectangular external form, wherein it through rectangular slots 24, 25a, 25b, 26a, 26b is subdivided in parallel linear web 21a to d and transverse- or rather connecting webs 22a, 22b, and 23a, 23b.
Therein the central rectangular slot 24 running in longitudinal direction of web plate 20 separates the both linear webs 21a, 21b which at it's ends through the connecting webs 22a,22b which run perpendicular to linear webs and stretch in direction of width of web plate are combined with each other. Consequently the linear webs 21a, 21b and the connecting webs 22a, 22b build a rectangular flat frame. In a central area of each linear web 21a, 21b or rather in its middle each a further connecting web 23a or rather 23b is arranged which produces the connection to the further neighbouring linear webs 21c or rather 21d. Therein the central connecting webs 23a, 23b are located in the middle between the linear neighbouring webs2la, 21c or rather 21b, 21d. The central connecting webs 23a, 23b are formed out between pairs of longitudinal slots 25a, 25b or rather 26a, 26b, which stretch from free borders of web plate 20 pair wise to inside.
Fig. 5a shows, that at both along side edges of web plate 20 plate shaped supports or rather support plates 11a, 11b are arranged each of which shows a bearing area 12a or rather 12b for connection with components or rather further construction or bearing components to be propped or rather held. The support plates 11a, 11b and to it associated bearing areas 12a or rather 12b are adjusted parallel to each other, wherein the bearing areas 12a, 12b show opposite directions. The spring component can for example be input in a bag support bearing of a helicopter tail rotor in such a way that the bearing area 12a is combined firmly with an internal surface of control bag 2 and the oppositely lying bearing area 12b is firmly combined with a side of belt 4.
The spring component is double-T-forming, wherein the web plate 20 stretches vertical between the support plate3 11a, 11b adjusted
parallel to each other. Through the special assambly of linear webs 21a to d and the connecting webs 22a,22b and 23a, 23b, the spring component is flexible in transverse direction. In Pig. 5b the possible bending direction is represented through the both arrows x, x . At a transverse bending moment MTrans. acting on the spring component which is Represented in Fig. sc in area of web plate 20 through the double arrows C, C corresponding to the Right - Hand - Rule, a transformation of bending moment to twisting moment takes place in linear web 21a, 21b or rather in centre area of spring component. Therein the linear webs 21a 21b are twisted in their course, each in area between the first connecting webs 22a, 22b and the further connecting webs 23a or rather 23b, lying opposite and arranged shifted for this.
The transverse bending strength of spring component is influenced essentially through the length L of linear web 21a, 21b. Greater the length 1 of a linear web is, lighter can it be twisted and even so less is it's transverse bending rigidity. The relation between the twist angle and the length 1 results from integration of formula.
Consequently through suitable selection of length 1 of linear web 21a, 21b each of the desired or rather optimum transverse bending rigidity of sming components can be attained.
The transverse expansion rigidity or rather support strength of spring component is essentially influenced through the breadth b of connecting webs 25a, 23b and through the height h of linear web 21a, 21b. Through suitable selection
-9-of parameter b and h the spring component with desired or rather optimum transverse expansion rigidity and support strength are created. Consequently it gives a transverse flexible support bearing- or rather spring component with the possibility of rigidity influence of through selection of measurements, particularly of the length 1 of linear web or rather of the length L of spring component.
In Fig, 6 schematically a cross section through a hag- support bearing as per invention in area of control bag 2 of a bearing less helicopter tail rotors is represented as it is for example shown in Fig. 1. Therein the control bag 2 builds in its inside a hollow space, in whose centre the belt 4 through two spring components as per invention is positioned. The spring components 8 prop, belt 4 from both sides opposite to internal wall of control bag 2. The support plates 11a of spring components are joined with control bag 2 through adhesive and / or bolting and the support plates 11b of spring components 8 are joined through adhesive and / or bolting with a surface of belt 4. Through such a storage of belt 4 between two spring components 8 a redundancy is attained that means at a failure of function of a spring component, for example through material fatigue or crack, the belt 4 is further positioned through the effect of second spring component firmly in the control bag 2.
The web plate 20 of spring component 8 are adjusted vertical to belt 4 and set up on the centre of belt 4. On ground of transverse flexibility of spring component 8 a twisting of belt 4 around it's longitudinal axis within the control bag 2 is possible. The twist movement is represented through the double arrows D in Fig. 6.
In Fig. 7a and 7b enlarged sections of front view and the side view of support bearing as per invention are shown. Both the spring components 8 are arranged symmetrical both sidewise of belt 4 of tail rotor and hold these between bearing areas 12b lying opposite to them. Therein the respective support walls of control bag 2, the bearing areas 12a and 12b of spring component 8 and the support area at tail rotor belt 4 are adjusted parallel to each other. The bag support bearing or rather the spring components as per invention are manufactured out of a fibre comnound material, through which to the extent possible an easy form of construction is achieved. It is also
to be considered, to produce them for example from metal.
Figure 3s ahows a further execution form of spring components as per invention. In this execution form the web plate 20 is provided with support plates 110a, 110b, whose out side lying sides are built as bearing areas 120a, 120b in which rectangular ion joints or rather 42 running in transverse direction of spring components are arranged. Through the expansion joints 41, 42, it is achieved that different thermal expansion co-efficients of spring components 9 and of components, with which it is combined do not lead to stresses or rather cracks or to a loosening of joints. Through the expansion joints 41, 42 the spring component 9 can match appearing relative movements between the components or rather between the components and support bearing.
The web plate 200 shows purely two linear webs 210a and 210b, whose ends are joined through connecting webs 220a and 220b. The further connecting webs 230a and 230b, which put on in centre of a linear web 210a, 210b are directly combined with support plates 110a or rather 110b without that further linear webs are located between the further connecting webs 230a, 230b and support plates 110a or rather 110b. Consequently the web plate 200 has the shape of wide, flat cross, whose cross bar is subdivided through a slot in two parallel running areas or rather plates or webs. In the Fig. 8b and 8c the spring component 9 is shown as per second execution form in a front or rather side view. The ratio of width b of connecting webs 23a, 23b to length 1 of linear web is about 1:5, wherein in general a range of 1:4 to 1:8 is specially preferred. The spring element can be extended in longitudinal direction, in order to match optimum the ratio of breadth b of connecting web 23a, 23b to length L of spring element 9 or rather to length 1 of linear web 21a, 21b. Consequently the rigidity of soring components through selection of sizes for example in longitudinal direction can be matched optimum. The expansion joints 41 and 42 make possible a better linking to the tail rotor belt, which for example are expanded through strong centrifugal - and/or bending forces, wherein the linking through adhesion, clamping or bolting can
In Figure 9, a highly exact space mirror with a frame support structure is represented. The frame support structure 80 is high module - Carbon fibre reinforced and mirror 90 shows at its backside reinforcement ribs 91, which are shaped like I honey comb. The mirror comprises of a SIC infiltrated Carbon fibre compound structure. The frame support structure 80 is combined with mirror 90 through three spring components 9 as per invention, as it was discussed above. Through the transverse bend flexible and thrust rigid spring component as co-nnecting component, also small relative movements between the frame support structure 80 and the mirror 90 can be equalised. Therein is also one S- forming twisting of web plate 20 or rather 200 over its breadth possible so that a mutual off set of both joining components transverse to web plate can take place, without that through it fracture, cracks or other impairment; can appear in spring components or parts connected with that. The connection between the frame support structure 80 and the mirror 90 through the spring components 9 as per invention takes place in 3 points, through which a stress free, stable storage of mirror 90 at the frame support structure 80 is possible.
The rectangular or square support plates 110b of spring components 9 are matched in honey comb hollow space, which are built between the reinforcement ribs 91. Through the slots or rather expansion joints 42 arranged in the support plates 110b, which are adjusted in present case transverse to web plates 200, a change of sizes of individual honey comb hollow spaces, which for example, appears on ground of temperature changes can be equalised.
With the present invention, spring components and support bearing are created which withstand high loads over a long time space, have a high transverse bend flexibility at stronger transverse elongation rigidity and support force and moreover can be manufactured at a simple and cost effective way. Expensive structure - or rather support components in the air - and space travel technology can be replaced by cost effective method wherein weak points are avoided and a
durable secure storage of moveable components, which are exposed to strong loads, is made possible. The spring components 3, 9 as per invention show in comparison to known elastomer bearing the advantage that they can be input in outer space, The spring components S, 9 as per invention show a high support force and a fecial favourable ratio of rigidity and they make possible a drastic reduction of manufacturing cost of bearing less helicopter tail rotor.
The invention is however not limited on spring components and support bearing in area of helicopter tail rotor or special travel mirror or rather outer space structures* It makes possible in general a supporting and cushioing storage of components, which execute the swivelling movements or relative movements in relation to a holding device wherein the mutual distance of components or rather bearing components remain constant and a high support force is guaranteed.
13 WE CLAIM
1. A spring component for a support bearing, particularly of helicopter tail rotor,
comprising at least two support components (113,116,110a, 110b) adapter
for joining individually with a plurality of propping components (2,4,80,90); a
web plate (20.200) which over its width joins the support components
(11a,11b, 110a,110b), the web plate comprising a first and second linear web
(21a, 21b, 210a, 210b) extending in longitudinal direction, a first connecting
web (22a, 22b, 220a, 220b) extending in direction of width connecting said
first and second linear webs to each other ,
characterized in that a second connecting web (23a,23b,230a,230b) stretching towards outside in direction to one of the support components (11a, 11b, 110a, 110b) is provided to a section laid between the first connecting web (22a, 22b, 220a, 220b) of at least one linear web (21a,21b, 210a,210b) so that a transverse bending moment acting on the spring components between the supportcomponents (11a, 11b, 110a, 110b) causes a twisting of at least one of said linear webs (21a,21b, 210a, 210b).
2. The spring component as claimed in claim 1, wherein both the linear webs
(21a,21b/210a,210b) are joined with each other via each of the first
connecting web (22a, 22b,220a,220b) and wherein each of the second
connecting web (23a, 23b, 230a, 230b) is disposed in the center of respective
linear webs (21a, 21b, 210a, 210b).
3. The spring component as claimed in claim lor 2, wherein the second
connecting web (230, 230b) forms a direct connection to the support
4. The spring component as claimed in claim 2, wherein the second connecting
web (23a, 23b) is connected with a third linear web (21c, 21d) which forms a
direct connection between the support component (11a, 11b) and the second
5. The spring component as claimed in one of the preceding claims, wherein the web plate (20, 200) has essentially a rectangular shape, and wherein the first linear web (21a, 21b) and the first connection web (22a, 22b) through at least one slot (24) extending in longitudinal direction are configured in the web plate (20).
6. The spring component as claimed in one of the preceding claims, wherein the second connecting web (23a, 23b) is formed through two slots (25a, 25b, 26a, 25b) extending from the free borders of the web plate (20) being disposed one upon the other.
7. The spring component as claimed in one of the preceding claims, wherein the support components (11a,11b,110a,110b) comprise bearing area (12a, 12b, 120a, 120b) which respectfully lies in opposite direction and wherein the web plates (20, 200) is disposed vertical to the bearing area.
8. The spring component as claimed in one of the preceding claims, wherein in the support elements (110,110b) one or more expansion points (41, 42) are provided, which extend in transverse direction.
9. The spring components as claimed in one of the preceding claims, wherein a length (I) of the linear web (21a, 21b) is so selected that the spring component has the desired transverse bending rigidity.
10.The spring components as claimed in one of the preceding claims, wherein a breadth (b) of the second connecting web (23a,23b) and a height (h) of the first linear web (21a, 21b) is so selected that the spring component has the desired expansion rigidity.
11.The spring component as claimed in one of the preceding claims, wherein a breadth (b) of the second connecting web (23a, 23b) is 1/15 to 1/3 preferably 1/8 to 1/4 particularly preferred about 1/5 of the length (I) of the second web (21a, 21b).
12.The spring component as claimed in one of the preceding claims, comprises a fibre compound material.
13. A support bearing incorporating the spring component as claimed in claims 1 to 12.
This invention relates to a spring component for support bearing, of helicopter tail rotors or for support structures for use in outer space encompasses at least two contact support components (11a, 11b) for connecting with the members that are to be supported (e.g. a belt and a control sleeve of a helicopter tail rotor), as well as a web. plate (20), which extends between the contact support components (11a, 11b) and which includes a pair of lengthwise webs (21a, 21b) extending in a longitudinal direction. The lengthwise webs are connected to each other by first connecting webs (22a, 226), Respectively, a further connecting web (23a, 23b) is arranged at a section of the two lengthwise webs (21a, 21b)
positioned between the first connecting webs (22a, 22b), wherein each further connecting web extends outwardly toward one of the support components (11a, 11b). In connection with a transverse bending moment acting on the spring component, a twisting of the lengthwise webs (21a, 21b) takes place. The spring component is flexible for transverse bending and comprises a high supporting force. A support bearing for a helicopter tail rotor or a support structure for use in outer space encompasses two or more of the spring components. In a control sleeve bearing of a helicopter tail rotor the belt is held in the control sleeve between two oppositely positioned spring components.
|Indian Patent Application Number||1934/CAL/1998|
|PG Journal Number||N/A|
|Date of Filing||30-Oct-1998|
|Name of Patentee||EUROCOPTER DEUTSCHLAND GMBH,|
|Applicant Address||81663 MUNCHEN,|
|PCT International Classification Number||B64C 27/48|
|PCT International Application Number||N/A|
|PCT International Filing date|