SE467305B

SE467305B - Aircraft propeller having automatic adjustment of the blade angle

Info

Publication number: SE467305B
Application number: SE8700192A
Authority: SE
Inventors: Per Olof Lissmyr
Original assignee: Olof Lissmyr
Priority date: 1987-01-20
Filing date: 1987-01-20
Publication date: 1992-06-29
Also published as: SE8700192D0; SE8700192L

Abstract

Adjustable propeller for aircraft, wind-propelled power stations, boats and the like, comprising propeller blades rotatably mounted on a hub unit for rotation about axes essentially parallel with the respective propeller blade. On the butt end, mounted in the hub unit, of each propeller blade there is disposed an eccentrically located stop 5,37 and on the hub unit there are disposed spring members 7,30 clamped in position between a counter- stay member 6,31, which can be fixed such that it is adjustable relative to the frame 1 of the hub unit, and a driver part 4,36, which is displaceable relative to the said frame and which has driver sections set up to engage with the stops 5,27 disposed eccentrically on the propeller blades in order to turn the propeller blades automatically towards lower or higher pitch, depending upon the resistance of the medium in which the propeller is operating. <IMAGE>

Description

Genom att hela distansen (3) ligger bakom den.D-ställda' delen av bladbredden Fig.3 som är lagrad i punkt (4),så kommer denna del av propellerbladet att reagera.med luft- tätheten som uppstår vid rotation av propellern. Vid lågt rotaticnsvarv är Jufttätheten lägre varför retur - Fjädern (6) kan trycka fram bakkanten på bladet (5) Fig.4, och därmed ställa in en större vinkel på bladet. Ökar man rotationsvarvet så ökar lufttätheten framför bladet.Ejädern (6) kommer då att tryckas ihop och där- med ställa in en lägre vinkel på bladet. Om man nu sän- ker varvet på propellerbladet så minskar luftätheten igen mot bladet (5). Fjädern (6) kan nu trycka Fram bakkanten på bladet (5) igen och därmed ställa om till en större vinkel. Stopparna (9) bestämmer max och min. inställning. Because the entire distance (3) lies behind the D-set part of the blade width Fig.3 which is stored in point (4), this part of the propeller blade will react with the air tightness which occurs when the propeller rotates. At low rotational speed, the air density is lower, which is why the return spring (6) can push the rear edge of the blade (5) Fig.4, and thus set a larger angle on the blade. If you increase the rotation speed, the air tightness in front of the blade increases. The spring (6) will then be compressed and thus set a lower angle on the blade. If you now lower the speed of the propeller blade, the air tightness against the blade decreases again (5). The spring (6) can now push the front trailing edge of the blade (5) again and thus adjust to a larger angle. The stops (9) determine the max and min. attitude.

Variationen av lufttätheten som uppstår mot bladet (5) Fig.4 vid olika rotationshastigheter och returkrafterna från fjädern (6) är de två faktorer som bestämmer blad- vinkelinställningen på propellern. Belastningen på pro- pellerbledet (5) och rätt inställd returfjäder (6) stäl- ler alltid in den rätta bladvinkeln. 3 vi 467 eos Alternativ 2, Fig. 5-6 och 7, är en utveckling av Alt.1 där regulatorfjädrarna lagts i en plastränna För att min - ska friktionen emellan Fjädern och ytterväggen på botten - plattan. Friktionen blir så gott som obefintlig, vilket höjjer känsligheten För regulatorn. Plastrännen är upp- lagrad med 4 st. kullager i bottenplatten och som löper'i ett spår i plastrännan. På innerkanten på plastrännan finns kuggsegment som griper in i motsvarande kuggsegment som är monterade via en klam ikring bladaxeln. När propel- lerbladen vrids så kommer plastrännan via kuggsegmenten att vridas runt och spänner därmed regulatorfjädrarna.The variation of the air tightness that occurs against the blade (5) Fig.4 at different rotational speeds and the return forces from the spring (6) are the two factors that determine the blade angle setting on the propeller. The load on the propeller blade (5) and the correctly set return spring (6) always set the correct blade angle. 3 vi 467 eos Alternative 2, Figs. 5-6 and 7, is a development of Alt.1 where the regulator springs are placed in a plastic chute In order to reduce the friction between the spring and the outer wall of the bottom plate. The friction becomes virtually non-existent, which increases the sensitivity of the regulator. The plastic gutter is stored with 4 pcs. ball bearings in the base plate and which run in a groove in the plastic gutter. On the inner edge of the plastic gutter there are tooth segments that engage in the corresponding tooth segments which are mounted via a clamp around the blade shaft. When the propeller blades are rotated, the plastic chute via the gear segments will be rotated around and thus tighten the regulator springs.

FIG. 5-6 och 7, visar bottenplattan2J, nav För upplagring EV_Eladaxlarna22, bladaxel23, kullager för upplagring av plastrännan24, regulatorFjädrarna25, klam med kuggsegment 26, låsskruvZ7, klam2B, armarna 31, som utgör reglerbart stoøp för fjädrarna 39, den fasta gaveln i plastrännan 32, stoppklack för max osh min. vridning 33, vridningsavstând i grader för inställning av bladvinkeln 3ä, kuggsegment å plastränna 36; spinner 35.FIG. 5-6 and 7, show the base plate2J, hub For bearing EV_Ela shafts22, blade shaft23, ball bearings for bearing the plastic chute24, regulatorFeathers25, clamp with tooth segment 26, locking screwZ7, clamp2B, arms 31, which form an adjustable casting for the springs 32 in the spring 39, , stop heel for max osh min. rotation 33, rotation distance in degrees for setting the blade angle 3ä, tooth segments on the plastic chute 36; spinner 35.

Claims

10 15 20 »25 30 35 4 PATENT REQUIREMENTS

Device for adjustable propellers for aircraft, wind turbines, boats and the like, comprising propeller bodies rotatably mounted with their root ends in a hub assembly for rotation about axes which are substantially parallel to the respective propeller blades and located closer to the front edge than the rear edge of the respective propeller blades, wherein spring means (7; 30) are clamped between a frame of the relatively hub unit adjustable fixable abutment means (6: part 31) and a relatively displaceable carrier (4, 10; 25, 36), which has carrier portions arranged to engage with abutments (5; 37) arranged eccentrically at the propeller blades, in order to, automatically depending on the resistance of the medium in which the propeller operates, automatically turn the propeller blades towards lower or higher pitch, e-characterized in that the carrier part (4, 10; 25, 36), the retaining member (6; 31) and the intermediate spring means (7; 30) are placed cooperating in a position behind the propeller. owned area, a circumferential space in this area, at a radial distance from the axis of rotation of the propeller, being used for locating the spring means (7; 30).

Device according to claim 1, characterized in that the eccentrically arranged abutments (5; 37) from the root ends of the propeller blades extend into said area for co-operation with the carrier part (4, 10; 25, 36).

Device according to claim 1 or 2, characterized in that the spring means (30) are arranged arcuately curved, each in a friction-reducing groove (25), which is arcuate and runs in a circular arc-shaped, peri- fert groove in a base plate (21) forming the base of the hub assembly.

Device according to claim 3, characterized in that each chute (25) has a rack (36) which cooperates with a rack segment, which forms an eccentrically arranged stop (33) of a propeller blade.

5. Device according to claim 3 or characterized in that the gutter (25) is made of plastic. 467 305

Device according to one of Claims 3 to 5, characterized in that the gutter (25) is supported in the base plate (21) by means of ball bearings (24).

Device according to any one of claims 3 to 6, characterized in that each of the spring means (30) has one end abutting against a fixed end (32) in the gutter and its other end abutting against a portion of the said abutment member (31).