CN1932250A

CN1932250A - Improvement of bladed rotor wheel for reinforcing blade locking

Info

Publication number: CN1932250A
Application number: CNA2006100806329A
Authority: CN
Inventors: 尼古拉斯·特里考奈特; 马修·考彻特克斯; 克劳德·莱亚斯
Original assignee: SNECMA SAS
Current assignee: Safran Aircraft Engines SAS
Priority date: 2005-05-26
Filing date: 2006-05-23
Publication date: 2007-03-21
Also published as: CA2548603A1; JP2006329189A; DE602006001786D1; EP1726786B1; EP1726786A1; FR2886336B1; RU2006118103A; FR2886336A1; JP5063034B2; US20060269417A1

Abstract

The wheel has a reception groove (14) including an upstream annular lip and a downstream annular lip defining an upstream annular cavity (20) and a downstream annular cavity (21). The upstream annular cavity includes a deeper annular hollowed-out portion (24) that extends beyond the bottom of the groove. The hollowed-out portion receives blade roots presenting upstream heels of greater volume. Latches (32) mounted in the groove include bases having upstream ribs (60) for engaging in the hollowed-out portion.

Description

Be used to strengthen the improvement of the bladed rotor wheel of blade degree of blocking

Technical field

Present invention relates in general to a kind of turbo machine, for example the rotor of the low pressure compressor in the turbojet engine with rotor of forming by the vaned impeller of an assembling.The invention particularly relates to improved the vanes fixed effect improvement especially when serious accident takes place.

Background technique

The European patent document 1496206 of the applicant's application has disclosed the shape of groove to admitting the significance of blade root, and this groove is formed in the rotor wheel circumference.This problem is even more important for the impeller that blade is in the conical flow, and that's how things stand for last what the impeller of the low pressure compressor in twin shaft bypass (by-pass) turbojet engine.What taper in the end is fairly obvious, and the face run-off the straight that these several grade blades are vertical with running shaft is promptly tilted with the centrifugal force direction.Do the danger increase that the in this manner stressed meeting of blade is become flexible blade if this direction takes place accident.

Existing document is touched upon in more detail with falling trapezoidal fastening piece with the problem of vanes fixed in the impeller groove, groove is made of lip edge, upstream and lip edge, downstream, these two edges link to each other to form upstream and downstream annular recess separately, the appropriate section of blade root recess engagement therewith at bottom land.Proposed connection area between bearing surface by deepening lip edge, upstream and the bottom land and it can be installed have the blade that upstream side helps and improve the blade hold facility in the document, this side rib has the bottom of big volume, and other remains unchanged.Therefore, side rib can be below lip edge, upstream below oblique more deeply being engaged in the darker annular recess.This modification helps limit blade to fly away from the danger of groove when serious impulse force takes place.

Also can when overhaul, change the shape of its recess to existing impeller with machine-tooled method.

Blade is installed also need one be on the annular lip edge insertion breach is being arranged on the circumference in the groove.More particularly, breach is formed in the annular lip edge, upstream, and it is used to make each blade root to insert receiving channel along the groove slippage at described blade before its final position.

For making blade keep stable, prevent it after assembling along circumferential movement, must around groove, load onto lock pin in the breach both sides.Guarantee that like this blade can not move rearwards to the place of aliging with breach, because if will cause blade from impeller, to eject like this.

Saw already that if near the blade the relief area has an accident, impulse force will make annular lip edge, upstream that local deformation is taken place, thereby receiving channel expansion, cause lock pin to fly ease.This danger may cause accident to take place, because in the case, blade can be once more along circular movement in receiving channel, and flies out after they reach the insertion groove position one by one.

Summary of the invention

The present invention attempts fixedly to prevent this main hazard by what improve lock pin.

The thought of foundation of the present invention is the lock pin shape that changes upstream annular lip edge, and strengthening its locking force in groove, so groove is when enlarging, and the gap between described lock and the groove be a negative value still, thus prevent lock pin fly escape.

More particularly, the invention provides a kind of bladed wheel that is used for turbine rotor, this impeller comprises the receiving channel of the root that is used to admit the blade relevant with impeller, described groove has annular lip edge, upstream and annular lip edge, downstream, place, limit at groove forms upstream annular recess and downstream annular recess, in this impeller, annular lip edge comprises the insertion breach that makes blade root can enter described receiving channel, simultaneously in the described receiving channel in described breach both sides, lock pin is installed, every lock pin is included in the backbone that extends between the upstream and downstream annular recess, impeller is characterised in that, for the described upstream annular recess that cut-out is arranged beyond bottom land, the backbone of each lock pin comprises the upstream rib-loop.

This rib-loop is cut the upstream recess more deeply, though when groove enlarges also fixing lock pin.

Though the Thickness Design of lock one-tenth has radial clearance and it is slided in groove when assembling (between breach and its mounting point), this gap allows described slip take place just, also like this in prior art constructions, owing to radially increase the slip of lock pin circumference when the upstream rib-loop can not under any circumstance all stop assembling in the described upstream extremity receiving channel degree of depth.

According to another favorable characteristics, described lock pin has two loss of weight breach that are formed on the backbone two ends.It also comprises screw.Screw is accepted in this hole.Screw withstands the blank wall between the two lip edges during assembling, is used for jack-up and lock pin is finally located, like this between two blade roots.Distance between two lock pins is that two blades are maintained fixed in the middle of their.

In a feasible embodiment, screw is formed on from the short column that backbone central authorities stretch out.

The present invention and advantage thereof can be by means of following list to give an example sub and to obtain better to understand with reference to accompanying drawing.

Description of drawings

Fig. 1 is the detailed perspective according to rotor wheel of the present invention;

Fig. 2 is the detail drawing that shows the radial section of lock pin and adjacent blades position separately;

Fig. 3 is the fragmentary, perspective view of the root of Fig. 2 blade of seeing from the bottom up;

Fig. 4 is the front view of lock pin;

Fig. 5 is that V along Fig. 4 is to the view of seeing; And

Fig. 6 is that VI along Fig. 4 is to the view of seeing.

Embodiment

In these figure, (Fig. 1) a part of rotor rotary drum (low pressure compressor of aircraft jet engine) of visible turbo machine often is called impeller (or wheel disc) 11.Carry many blades 12 (Fig. 3) on each impeller.Blade installation is in impeller 11 outer surfaces receiving channel 14 along the circumferential direction.Rotor is made up of many this blade-carrying wheels.The bottom of blade 12 constitutes the platform 15 of the part on the conical flow border of passing compressor, and blade root 19 is called " fall trapezoidal fastening piece ", and it extends its part width below described platform.Blade root 19 engagements also are installed in the described receiving channel 14 of impeller.The blade root position as shown in phantom in Figure 2.

Receiving channel 14 has annular lip edge 16, upstream and annular lip edge, downstream 18.These two lip edges form the annular recess 21 in upstream annular recess 20 and downstream respectively, mesh the blade root appropriate section therein, and platform 15 covers recess 14 parts.In case all blade is laid and put in place, the platform 15 of Fang Zhiing just constitutes the annular surface of compressor runner shoulder to shoulder.

In order to improve the soundness of blade in groove, the upstream annular recess 20 of groove comprises darker annular cut-out 24.In the example shown, this cut-out exceeds the bottom surface 26 of groove 14, in the darker wall thickness that enters impeller 11.The effect of this cut-out 26 is upstream heels of accepting big volume, thereby improves the soundness of blade when having an accident.

In addition, the assembling blade needs forming an insertion breach 30 (this example is lip edge, upstream) on the annular lip edge at groove at least on certain position of impeller 11 cylindricals.This breach is used for blade root 19 is sent in the groove 14 one by one.In case blade root enters in the groove, corresponding blade just slides into its final position along groove at circumferencial direction.In case blade assembling finishes, the root near two blades of breach 30 is positioned at the breach both sides at circumferencial direction.

Yet, for guaranteeing after the not meeting of blade along circumferential movement to the root that a slice blade is arranged just in time contraposition breach, can cause blade to fly ease like this, should prepare two keys of installation or lock pin 32 in groove 14, lock pin is fixed on the both sides of breach 30 at circumferencial direction, and their position and breach are equidistant.In Fig. 1, the position of lock pin 32 is marked by the polarizing

slot

36,38 on the

lip edge

16,18 that is respectively formed at breach 30 both sides.

The backbone 40 of each lock pin, its thickness are substantially equal to definite the radially sliding highly of receiving channel.In other words, for making lock pin lead to the final position that it is aimed at

otch

36,38 from the position that groove 30 is determined, the shape and size of groove 14 are (in radial section, the geomery of

recess

20,21 particularly), and the shape and size of backbone 40 determine that (breach 30) can be free to slide but radial clearance as far as possible little (required little gap) to rigging position (otch 36,38) promptly described backbone from the insertion position like this.

Backbone further comprises the guide protrusions 46,48 that its geomery is suitable with

otch

36,38 respectively.Visible upstream guiding recessed 46 and downstream guide protrusions 48 on the figure.When lock pin was in rigging position, projection 46,48 cooperated with otch 36,38.Available screw passes to prevent its motion on this position, and backbone extends radially with respect to groove 14 under the guiding of

otch

36,38, up to the bottom surface that the upstream and the downstream of backbone are withstood lip edge 16,18.Screw 50 is screwed in the screw 52 of lock pin itself and is screwed into backbone 40 and screw that the short column 54 that stretches out from described backbone central authorities forms.

In addition, lock pin has two and is formed on the backbone both sides, the loss of weight breach 56 that begins from its vertical limit.

The shape of lock pin is made the inclined-plane, upstream 57 and the inclined-plane, downstream 58 that leans against 18 belows, lip edge, downstream that lean against 16 belows, lip edge, upstream.Projection 46,48 is stretched out from these two inclined-planes.Inclined-plane, upstream 57 is flat and tilts at whole backbone thickness.

According to a noticeable feature of the present invention, the backbone 40 of each lock pin comprises upstream rib-loop 60, engaging-in cut-out 24 when it is suitable for assembling.The upstream rib-loop stretches out in the bottom on plane, upstream 57, and it surpasses the bottom surface of backbone 40.Although rib-loop 60 is arranged, lock pin still can enter in the groove 14 when assembling without difficulty, because cut-out 24 is arranged in upstream recess 20.

In case lock pin location (Fig. 2), owing to there is inclined-plane, screw thread 60 upstream can more be deep into below the lip edge, upstream.Therefore, even groove 40 has the tendency of expansion under the effect that is applied to one of adjacent blades active force, lock pin still is maintained in the groove 14.

The platform seamed edge 17 that is positioned at both sides, lock pin position has otch 62, and the top of short column 54 is deviate from so that tighten screw 50.

Claims

1, a kind of bladed wheel that is used for turbine rotor, this impeller comprises the receivability receiving channel of the root of impeller associated vanes (14) therewith, described groove (14) has annular lip edge, upstream and downstream ring edge, these two lip edges form upstream annular recess (20) and downstream annular recess (21) respectively at the place, limit of groove, in this impeller, should comprise the insertion breach (30) that can make blade root enter described receiving channel in annular lip edge, and lock pin (32) is installed in the described receiving channel of described breach both sides, each lock pin is included in the backbone that extends between the upstream and downstream annular recess, this impeller is characterised in that, for the described upstream annular recess that is included in bottom land cut-out (24) in addition, the backbone of each lock pin comprises upstream rib-loop (60).

2, bladed wheel according to claim 1, it is characterized in that, press traditional approach, has the polarizing slot (36 that is used for lock pin in the described annular lip edge of described breach (30) both sides, 38), described lock pin comprises guide hump (46,48), and the geomery of its geomery and associated otch is consistent.

3, bladed wheel according to claim 1 and 2.It is characterized in that described rib-loop (60) is determined by the clinoplain (57) that stretches out described backbone.

4, according to aforementioned any described bladed wheel of claim, it is characterized in that described lock pin has two the loss of weight breach (56) that are formed on described backbone both sides.

5, bladed wheel according to claim 4 is characterized in that, roughly forms screw (52) at described backbone center.