US3071691A

US3071691A - Shaft support

Info

Publication number: US3071691A
Application number: US32636A
Authority: US
Inventors: Mitchell J Haddad; Harold T Adkins
Original assignee: Curtiss Wright Corp
Current assignee: Curtiss Wright Corp
Priority date: 1960-05-31
Filing date: 1960-05-31
Publication date: 1963-01-01
Anticipated expiration: 1980-01-01

Description

Jan. 1, 1963 M. ,1. HADDAD ETAL 3,071,591

' SHAFT SUPPORT Filed May 51. 1960 INVENTORSI HAROLD I 40/0/86 BY five/1541. 11440040 m 2 $1M #M ATrOR/VEVJ United States Patent 3,071,691 SHAFT SUPPORT Mitchell J. Haddad, Detroit, and Harold T. Adkins, St.

Clair Shores, Mich., assignors to Curtiss-Wright Corporation, Utica, Mich., a corporation of Delaware Filed May 31, 1960, Ser. No. 32,636 2 Claims. (Cl. 290- 52) This invention relates to shaft supporting means in general, and more particularly to means for supporting a rotating shaft with minimum external surface obstruction.

In many instances it is desirable to have a shaft member supported for rotation in such a manner that the shaft supporting means occupies a minimum of space and is obscurely disposed. This is particularly true in gas fired turbines where the impeller supporting shaft extends across the air intake passage.

The present invention is shown as employed to support a turbine rotor shaft which has the turbine rotor provided on one end thereof and a generator rotor member provided thereon across an air intake passage from the turbine rotor. Obviously, there is'no readily apparent way to support the rotor shaft without obscuring the air intake passage or changing the preferred form of the turbine and generator rotor structures. Further, the overhung weight of the turbine rotor and the rigidity of the support required therefore creates a special problem.

It is an object of this invention to teach a new and novel means of supporting a rotary shaft.

It is an object of this invention to teach a rotary shaft supporting means with minimum external surface obstruction and balanced load carrying potential.

It is also an object of this invention to teach a rotary shaft supporting means which includes the aforementioned features and is readily adapted for accessory driving purposes. v

It is a further object of this invention to teach a rotary shaft supporting means which is sturdy and compact in construction and arrangement.

These and other objects and advantages in the practice of this invention will be more apparent upon a reading of the'following description of a working embodiment of the invention in conjunction with the study of the accompanying drawings, wherein;

FIGURE 1 is a cross-sectional view of the shaft supporting means proposed as incorporated within a compact turbine driven high-speed generator set.

FIGURE 2 is a schematic illustration of the shaft supporting means which is presented separately for a clearer understanding thereof.

A gas fired turbine is shown by FIGURE 1 as adapted to drive a high speed generator 12.

The turbine 10 includes a housing assembly 14 having a combustion liner 16 disposed therein and forming induction passages 18 to the fuel injection and vaporizor head (not shown). The housing end 20 is adapted to have the dilfuser assembly 22 engaged thereto for directing compressor air to the induction passages 18. Within the throat 24 of the housing assembly is disposed the rotor assembly 26 which includes the turbine rotor 28 and compressor rotor 30. These rotors are secured together and include turbine and compressor vanes 28' and 30', respectively. Combustion exhaust gases escaping over the turbine vanes 28 drive the rotor assembly 26 and in turn cause air to be inducted and compressed by the compressor vanes 30 for supply to the turbine housing.

A compressor inlet spider 32 is secured to the housing end wall 20 next adjacent the throat 24 thereof. This member provides the intake passage 34 leading to the compressor 30.

lice

It will be noted that the intake passage 34 is unobstructed and that the rotor assembly 26 appears to be disposed in cantilever supported relation from some position completely removed therefrom. This is an important aspect of the present invention and is well illustrated in this embodiment.

The stator assembly 36, of the generator 12, is disposed next adjacent to the inlet spider 32 and the rotor shaft support plate 38 is in turn secured thereto. Actually, the stator assembly 36 is trapped and held in shouldered engagement between the support plate 38 and the inlet spider 32 by the tie rods or bolts 40 which are engaged with the housing end wall 20.

The rotor assembly 26 includes the turbine and

compressor rotors

28 and 30, respectively, and as mentioned, which are secured together by a lock nut 42. The compressor rotor 28 includes a tubular section 44 which extends through the compressor intake passage 34 and terminates next adjacent the generator section 12. A tubular lock shaft 46 is sleeved within the compressor section 44 and in threaded engagement therewith. This extends the rotor assembly 26 into the generator section 12 and provides a support for the generator rotor 48. The generator rotor 48 is keyed to the lock shaft 46 and is locked axially by the lock nut 50 threaded on the end thereof.

The generator rotor 48 is disposed concentrically within the stator 36 of the generator and, obviously, is required to be maintained in extremely close centered relation thereto.

The stator assembly 36 of the generator 12 will be noted to include current conductive windings 52 which extend into a recessed part 54 of the support plate 38. These windings are kept cool by having the generator rotor lock nut 50 formed to include impeller blades or fins 56 to induct air through openings 58 in the support plate and cause an air cooling circulation through the generator in the course of rotor assembly operation.

The rotor assembly 26, besides the structure thus far described, includes a rotor shaft 60 having a head portion 62 shouldered within the tubular section 44 of the compressor rotor 28 and locked by the tubular lock shaft 46. The rotor shaft 60 is provided with

ball bearing members

64 and 66 near opposite ends thereof. The ball bearing members are spaced by' separators 68 keyed to the rotor shaft.

' A tubular support 70 is concentrically disposed in fixed spaced relation within the rotor assembly 26. It is disposed with one end thereof in a cantilever supported position by having a flange 72 near the other end thereof engaged to the support plate 38 by a lock nut 74. The outer races of the

bearings

64 and 66 are engaged with the support member 70 and, accordingly, the rotor shaft 60 is rotatably supported therein and the rotor assembly 26 is in turn rotatable with the shaft.

The disclosed rotor supporting assembly is shown schematically by FIGURE 2.

The massive part of the rotor assembly 26 is shown in phantom outline and is identified as 26. The supported part of the assembly is shown as inclusive of an integral rotor shaft 60', head 62 and lock shaft 46 identified as 26". The support tube 70 is shown as inclusive of the support plate 38 and having the tubular part thereof received within the annular space between the shaft 60' and the lock shaft part 46'. The bearings 64' and 66 are disposed between the support tube and the stub shaft 60' as previously described.

In the particular embodiment shown, the use of an elongated rotor supporting shaft' in order to have the hearing 64 disposed outside of the air intake passage, is no longer necessary. The support tube 70 enables the bearing to be disposed within the air intake but in an unobstructive manner. It is further significant, in this particular embodiment, that there is no overhung weight on the

bearings

64 and 66 since the mass of the turbine and compressor rotors, 28 and 30, is essentially balanced by the mass of the generator rotor 48 (which, while less, is farther removed therefrom).

Aside from the advantages previously discussed, the disclosed assembly also affords a structure having improved bearing life since the inner bearing races are rotated rather than the outer races. This effects a lesser rotational velocity of the ball bearings and accordingly a longer life therefor than with an outer race rotating assembly. Further, with grease packed bearings, an

outer race rotating structure causes a centrifuge of lubricant towards the outer race and makes the bearings work through the lubricant, causes throw-out problems, etc. The proposed arrangement obviously avoids these problems.

It is also apparent that the open end of the support tube 70 affords a ready means of drive connection for accessories or other power take-off means.

While a preferred form of this invention has been described andillustrated, it will be appreciated that varia tions and modifications thereof may be made thereto without departing from the teachings herein. Such of these variations, modifications and improvements as incorporate. the principals and spirit of this invention are to be considered as included within the hereinafter appended claims unless such claims by their language expressly state otherwise.

We claim:

1. A turbine rotor assembly and support therefor comprising: a turbine rotor having a stub shaft provided on one end thereof, a compressor rotor received immediately next adjacent said turbine rotor and including a hub portion receiving said stub shaft in locked engagement therewithin, said compressor rotor having the hub por' tion thereof extended on the side thereof away from said turbine rotor and having a rotor shaft provided therein, said'rotor shaft being concentrically disposed within said extended hub portion and having the end thereof next adjacent said turbine rotor secured to said hub portion in spaced relation to said turbine rotor and the stub shaft end'thereof for minimal heat transfer thcr ebetween, tubular support member received within the extended hub portion of said compressor rotor and in concentric;

and; heat dissipating spaced relation to the inner Walls thereof and about said rotor shaft, and ball bearing mean Provided withinsaid support member for rotation al support of said rotor shaft centrally therewithin and of 'said turbine and compressor rotors engaged therewith.

2. A unified turbine generator and rotor assembly and support for use within a turbine cornbustor and generator housing, and comprising: a turbine rotor for support within the combustorpart; of said housing, a compressor rotor provided immediately next adjacent said turbine rotor at the intake of to said combustor and for engagement with said turbine rotor, said turbine rotor including a stub shaft and said; compressor rotor having a hub receiving the stub shaft of said turbine rotor in locked engagement therein, said compressor rotor having the hub portion thereof extended on the side thereof away from said turbine rotor and into the generator part of said housing, a rotor shaft provided within said extended hub.

portion and between the ends thereof, said rotor shaft being concentrically disposed within said extended hub,

portion and having the end thereof next adjacent said turbine rotor secured to said hub portion in spaced rela;

tion to said turbine rotor and the stub shaft end thereof; for minimal heat transfer therebetween, a tubular support member open at opposite ends. and engaged at one end to the generator part of said housing, theother end,

of said supportmember being received within the extend,

ed hub portion of said compressor rotor and in concentric and heat, dissipating space relation to the inner walls. thereof and about said rotor shaft, ball bearing means,

provided within said support member for rotational sup: port of said rotor shaft centrally therewithin and of said! turbine and compressor rotors engaged therewithand a; generator rotor provided on the extended end of said hub, within the generator part of said housing on theot her side of the intake to said combustor and counterbalancr ingthe overhung weight of said. turbine and compressor rotors in the course of rotation with said rotor shaft.

References Cited in the file of this patent UNITED STATES PATENTS.

Germany Mar. 112, 1 942

Claims

2. A UNIFIED TURBINE GENERATOR AND ROTOR ASSEMBLY AND SUPPORT FOR USE WITHIN A TURBINE COMBUSTOR AND GENERATOR HOUSING, AND COMPRISING: A TURBINE ROTOR FOR SUPPORT WITHIN THE COMBUSTOR PART OF SAID HOUSING, A COMPRESSOR ROTOR PROVIDED IMMEDIATELY NEXT ADJACENT SAID TURBINE ROTOR AT THE INTAKE OF TO SAID COMBUSTOR AND FOR ENGAGEMENT WITH SAID TURBINE ROTOR, SAID TURBINE ROTOR INCLUDING A STUB SHAFT AND SAID COMPRESSOR ROTOR HAVING A HUB RECEIVING THE STUB SHAFT OF SAID TURBINE ROTOR IN LOCKED ENGAGEMENT THEREIN, SAID COMPRESSOR ROTOR HAVING THE HUB PORTION THEREOF EXTENDED ON THE SIDE THEREOF AWAY FROM SAID TURBINE ROTOR AND INTO THE GENERATOR PART OF SAID HOUSING, A ROTOR SHAFT PROVIDED WITHIN SAID EXTENDED HUB PORTION AND BETWEEN THE ENDS THEREOF, SAID ROTOR SHAFT BEING CONCENTRICALLY DISPOSED WITHIN SAID EXTENDED HUB PORTION AND HAVING THE END THEREOF NEXT ADJACENT SAID TURBINE ROTOR SECURED TO SAID HUB PORTION IN SPACED RELATION TO SAID TURBINE ROTOR AND THE STUB SHAFT END THEREOF FOR MINIMAL HEAT TRANSFER THEREBETWEEN, A TUBULAR SUPPORT MEMBER OPEN AT OPPOSITE ENDS AND ENGAGED AT ONE END TO THE GENERATOR PART OF SAID HOUSING, THE OTHER END OF SAID SUPPORT MEMBER BEING RECEIVED WITHIN THE EXTENDED HUB PORTION OF SAID COMPRESSOR ROTOR AND IN CONCENTRIC AND HEAT DISSIPATING SPACE RELATION TO THE INNER WALLS THEREOF AND ABOUT SAID ROTOR SHAFT, BALL BEARING MEANS PROVIDED WITHIN SAID SUPPORT MEMBER FOR ROTATIONAL SUPPORT OF SAID ROTOR SHAFT CENTRALLY THEREWITHIN AND OF SAID TURBINE AND COMPRESSOR ROTORS ENGAGED THEREWITH, AND A GENERATOR ROTOR PROVIDED ON THE EXTENDED END OF SAID HUB WITHIN THE GENERATOR PART OF SAID HOUSING ON THE OTHER SIDE OF THE INTAKE TO SAID COMBUSTOR AND COUNTERBALANCING THE OVERHUNG WEIGHT OF SAID TURBINE AND COMPRESSOR ROTORS IN THE COURSE OF ROTATION WITH SAID ROTOR SHAFT.