US2884186A - Rotor construction for axial flow compressors - Google Patents

Description

D. J. CLARKE 2,884,186.

ROTOR CONSTRUCTION 'FOR AXIAL 110w COMPRESSORS April 28, 1959 Filed April 25. 1954 INVENTOR. W M

United States Patent ROTOR CONSTRUCTION FOR AXIAL FLOW- COMPRESSORS Daniel J. Clarke, Bay City, Mich. assignor to The Stalker Corporation, a corporation of Michigan Application April 23, 1954, Serial No. 425,132

6 Claims. (Cl. 239-134) This invention relates to axial flow compressors.

An object of the invention is to provide an axial flow rotor of light and economical construction. ,7

Another object is to provide a rotor for axial flow compressors comprising sheet metal blades.

Other objects will appear from the description, drawings and claims.

The above objects are accomplished by the means illustrated in the accompanying drawings in which- Fig. 1 is a fragmentary axial section of a compressor incorporating a rotor according to this invention;

Fig. 1a is a fragmentary. axial section of an end disk and the adjacent ring;

Fig. 2 is a fragmentary development of the outer surface of the rotor at the root ends of the blades;

Fig. 3 is an axial front view of a rotor wheel;

Fig. 4 is a fragmentary section of the rotor near the blade roots taken on the line 44 of Fig. 2;

Fig. 5 is a fragmentary section on line 5-5 in Fig. 2;

Fig. 6 is a fragmentary axial section through the compressor; and

Fig. 7 is a section on line 77 in Fig. 6.

Referring to the drawings a fragment of a compressor is shown in Fig. 1. It comprises the rotor 2 mounted in the case means 4 for rotation about the axis of shaft 6 borne in the bearing 8. When rotated the rotor induces a flow of fluid through the inlet 9 and through the annular duct 10 defined between the rotor 2 and'the case means 4. The rotor blades 12 are of light hollow sheet metal construction and divide this duct 10 into rotor flow passages between the rotor blades.

As shown particularly in Figs. 2-6, the rotor is comprised of a wheel for each rotor stage which in turn is comprised'of rings like 13 and 14 whose teeth 15 mesh to position one relative to the other and to transmit torque therebetween.

The rings are clamped between two end disks 16 and 17 by the tie rods 23. These tie rods pass through aligned apertures in radially inwardly extending flanges 13a and 14a respectively. The disk 17 is at the rear end of the series of rings forming the rotor.

The adjacent rings have notches 18 and 19 which register to define an opening 20 for receiving the roots of the blades which have enlarged portions 21 thereon as shown in Fig. 4. At the localities of the blade roots the rings are thickened to provide for the sockets 22 which house the blade roots.

The blades are mounted for oscillation about the center of the arcuate surfaces 24. Their oscillation or vibration is damped by the damper wire 26 which preferably passes through the bearing 28 in sliding relation thereto. The bearing is fixed to the stem 30 of the blade 12. See Figs. 3, 4, 6 and 7 particularly. When the rotor is in operation centrifugal force presses the wire outward and mag nifies the frictional efiect between the wire and the hearing 28. This damps the vibration of the blades.

The wire could also be fixed in the element 28. Then the out-of-phase vibration of the blades tends to damp one another.

The rotor structure disclosed is very light since the material is positioned chiefly in the rim of the rotor, that is at the rings. Also the driving torque is applied sub stantially at the rim of the rotor where the driving forces can be a minimum.

If the blades are made hollow particularly of sheet metal construction, their weight is small so that the centrifugal loads at their roots are small. They can accordingly be supported by simple rings without hub disks extending across their encircled space. The radial thickness of the rings can be and is preferably only a small fraction of the order of 0.5 times the maximum radius of the ring.

The rings such as 13 and 14 can be recessed as at 32 and 34 to receive the shroud rings 38 at the tips of the stator blades 42 and 44.

It will now be clear that the structure is light since the wheel material is concentrated at the rotor rim where it is most effective in driving the blades; also that the structure is simple and economical to produce by standard machine tools and the like.

While I have illustrated specific forms of the invention, it is to be understood that variations may be made therein and that I intend to claim my invention broadly as indicated by the appended claims.

What is claimed is:

l. A rotor for an axial flow compressor adapted for operation in a case comprising a plurality of bladed rotor wheels arranged in side by side relation, each said wheel including a pair of rings of narrow radial width and peripherally spaced axial flow blades carried thereon, said rings having a plurality of peripherally spaced notches therein to define a series of blade openings, said blades having root portions extending into said openings for guiding and supporting said blades in operative relation upon said wheels, said openings having arcuate surfaces engageable by said root portions of said blades providing for limited oscillatory movement of each said blade in its said opening, said rings being formed with interfitting surfaces on adjacent faces providing for transmission of torque from one wheel to another independently of the support for said blades, a pair of end disks enclosing the outer faces of said wheels forming the support therefor, and shaft means for rotatably mounting said end disks.

2. A rotor for an axial flow compressor adapted for operation in a case comprising a plurality of bladed rotor wheels arranged in side by side relation, each said wheel including a pair of rings of narrow radial width and peripherally spaced axial flow blades carried thereon, said rings having a plurality of peripherally spaced notches therein to define a series of blade openings, said blades being hollow and having root portions extending into said openings for guiding and supporting said blades in operative relation upon said wheels, said openings having arcuate surfaces engageable by said root portions of said blades providing for limited oscillatory movement of each said blade in its said opening, stems extending into said hollow blades and projecting radially inwardly of said rings, means engaging the radially inner portions of the series of said stems to damp the vibrations of said blades, said rings being formed with interfitting surfaces on adjacent faces providing for transmission of torque from one wheel to another independently of the support for said blades, a pair of end disks enclosing the outer faces of said wheels forming a rotor assembly thereof, and shaft means for rotatably mounting said end disks.

3. In combination in an axial flow compressor for impelling a flow of elastic fluid therethrough, a rotor mounted for rotation about an axis, said rotor comprising spaced end disks, shaft means for rotatably supporting said end disks for rotation about said axis, a plurality of bladed rotor wheels positioned in series between said end disks, each said wheel comprising a ring of narrow axial. Width, means fixing said rings to said end disks to receive a driving torque therefrom to rotate them at high blade tip speeds to cause a substantial increase in density and pressure of said fluid, some of said rings having teeth on the axial end thereof interfitting with the teeth of the next adjacent ring for transmission of torque therebetween, each said ring of a pair of said rings with interfitting teeth having a plurality of peripherally spaced notches registering one with another to define a plurality of blade openings, peripherally spaced hollow sheet metal axial flow blades carried by said rings and extending outwardly through said openings, and means adjacent the circumference of said rings and disposed between a pair of said rings which form a wheel and radially outwardly of said axis supporting said blades entirely from said rings and independently of said teeth.

4. In combination in an axial flow compressor for impelling a flow of elastic fluid therethrough, a rotor mounted for rotation about an axis, said rotor comprising spaced end disks, and a plurality of bladed rotor wheels positioned in series between said end disks, each said wheel including a ring of narrow axial width, means fixing said rings to said end disks to receive a driving torque therefrom for rotation at high blade tip speeds to cause a substantial increase in density and pressure of said fluid, some of said rings having teeth on the axial end thereof interfitting with the teeth of the next adjacent ring for transmission of torque therebetween, each said ring of a pair of said rings with interfitting teeth having a plurality of peripherally spaced notches registering one with another to define a plurality of blade openings peripherally spaced hollow sheet metal axial flow blades carried on said rings and extending outwardly through said openings, said blades being of light hollow sheet metal construction limiting the centrifugal loads on said rings during said rotation and adapting each said ring to have said narrow width less than about 5 percent of the maximum radius of said rings, and means adjacent the circumference of said rings and disposed between a pair of said rings which form a wheel and radially outwardly of said axis supporting said blade entirely from said rings and independently of said teeth.

5. In combination in an axial flow compressor for impelling a flow of elastic fluid therethrough, a rotor mounted for rotation about an axis, said rotor comprising spaced end disks, and a plurality of bladed rotor wheels positioned in series between said end disks, each a} said wheel including a ring of narrow radial width, means fixing said rings to said disks to receive a driving torque therefrom, some of said rings having clutch teeth on the axial end thereof interlitting with the teeth of the next adjacent ring for transmission of torque therebetween, each said ring of a pair of said rings with interfitting teeth having a plurality of peripherally spaced notches registering one with another to define a plurality of blade openings, peripherally spaced axial flow blades carried in said blade openings, said blades having enlarged portions at the roots thereof, and means forming sockets in said rings for receiving said blade enlargements therein.

6. In combination in an axial flow compressor for impelling a flow of elastic fluid therethrough, a rotor mounted for rotation about an axis, said rotor comprising spaced end disks, and a plurality of bladed rotor wheels positioned in series between said end disks, each said wheel including a ringof narrow radial width, means fixing said rings to said disks to receive a driving torque therefrom, some of said rings having clutch teeth on the axial end thereof interfitting with the teeth of the next adjacent ring for transmission of torque therebetween, each said ring of a pair of said rings with interfitting teeth having a plurality of peripherally spaced notches registering one with another to define a plurality of blade openings, peripherally spaced axial flow blades carried in said blade openings, said blades having enlarged portions at the roots thereof, said rings being thickened to provide sockets for receiving said blade enlargements therein.

References Cited in the file of this patent UNITED STATES PATENTS 1,601,402 Lorenzen Sept. 28, 1926 1,891,948 Rice Dec. 27, 1932 2,641,440 Williams June 9, 1953 2,649,243 Stalker Aug. 18, 1953 2,655,307 Buckland et a1. Oct. 13, 1953 2,675,174 McDowall Apr. 13, 1954 2,717,554 Stalker Sept. 13, 1955 FOREIGN PATENTS 55,102 Netherland Aug. 16, 1943 138,839 Australia Sept. 26, 1950 439,567 Germany Jan. 14, 1927 543,557 Great Britain Mar. 3, 1942 853,988 Germany Oct. 30, 1952 872,816 Germany Apr. 9, 1953 1,056,070 France Oct. 21, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 23,884,186 April 28, 1959 Daniel J, Glarke It is herebfi certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2', line 14, for "O5 time's" read 0065 times column 3,,

lines 35 and Bo for "openings peripherally" read We openings, peripherally,

Signed and sealed this let day of September 1959 (SEAL) fittest:

KARL Em AXLINE Attesting Officer ROBERT C. WATSON Commissioner of Patents

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