US2514097A - Hub construction for variable pitch propellers or the like - Google Patents

Description

July 4, 1950 Y R. E. B. SHARP 2,514,097 HUB CONSTRUCTION FOR VARIABLE PITCH PROPELLERS OR THE LIKE Filed Jan. 14, 1947 v 2 Sheets-Sheet 1 Diaphragm unsfressed IN VEN TOR.

R. E B SHARP y 4, 1950 R. E. B. SHARP 2,514,097

HUB CONSTRUCTION FOR VARIABLE PITCH PROPELLERS OR THE LIKE Filed Jan. 14, 1947 2 Shee ts-Sheet 2 I I I ll 36 20 F/G. j

--28 f 1 23 LgU INVENTOR. E. E. B. SHARP Patented July 4, 1950 HUB CONSTRUCTION FOR PITCH PROPELLERS on T E LIKE Robert E. B. Sharp, York, Pa.,'assignor to S. Morgan Smith Company, York, Pa., a corporation of Pennsylvania Application January 14, 1947, Serial No. 721,944

Claims.

This invention relates to rotors having adjustable blades and more specifically to the construction of the hubs thereof.

An important object of the invention is the provision, in a construction of this type, of an arrangement whereby the bearings in which the adjustable blades are mounted and the operating connections by which adjustment of the blade position is obtained, can be fully and constantly lubricated.

Another and more specific object of the invention is the provision of a structure of this character wherein a hub, having internal bearings mounting a plurality of rotatability, adjustable blades projecting therefrom, is provided with a sealing means between the rotating blades and hub shell of such character that the hub structure is maintained as a sealed container without regard to the positional adjustment of thev blades.

A further and still more specific object of the invention is the provision means for maintaining within a hub of this character a pressure substantially equal to that to which the sealing means between the hub and blades is externally subjected.

These and other objects are obtained by the construction showed in the accompanying drawings, wherein, for the purpose of illustration, I have shown my invention as applied to a ship propeller hub, and wherein:

Figure 1 is a fragmentary longitudinal section through a propeller hub construction in accordance with my invention,

Figure 2 is a fragmentary sectional view taken on line 2-2 of Figure 1.

Figure 3 is a section similar to that of Figure 1 showing the operating shaft moved further into the hub, and

Figure 4 is a section on line i4 of Figure 1.

Referring more particularly to the drawings, the numeral Ill designates a shaft having a flange II by means of which it is attached as at l2 to hub l3, said hub mounting radial blades 14, only one of which is herein illustrated. The hub 13 comprises a shell [5, having an upper wall It engaged by securing the elements l2, sockets H, for the reception of the shanks l8 of blades l4, and a rear end closure l9, more particularly described hereinafter.

Shaft 16 is hollow and has directed therethrough means for rotating blades Id. In the present instance, the rotating means comprises a reciprocatory shaft 20, having bearing in the shell at 2| and having secured thereto a collar 22 including projecting arms 23 for connection to stems I8. Stems l8 are mounted in spaced bearings 24 and 25, supported by shell l5, and an extended tubular portion of the upper wall [3 respectively, and in the present instance have secured thereto, intermediate bearings 24 and 25, collars 21 linked at 28 to arms 23, whereby reciprocation of shaft 2c will result in rotative oscillation of the stems l8 and consequently of blades M. It is to be understood that this-means of oscillation of the blades is purely illustrative'and may be substituted for by any of the well-known means through which adjustable blades of this character are manipue lated. i

In accordance'with my invention, the hubs of blades l4 and the shell surrounding the hubs, are connected by'diaphragms 29, which may be constructed of any suitable substance which is resistant to an internal lubricant and the external fluid, and which is not only resilient but elastic to withstand distortion as hereinafter explained. ,This diaphragm is sealed by clampingmeans 30 at .itsperiphery to shell l5 and by clamping means 31 at its inner diameter to the hub of blade [4. Since the blade I4 is rotatably adjustable; the diaphragm is of material sufficiently elastic to withstand distortion between its normal operating position A shown in Figure 2, and its maximum adjustment positions, in-

dicated at B and C respectively, the diaphragm 29 being undistorted at the medial or operating position A for obvious'reasons.

The hub shell, and more specifically the end cap of closure I9 ,theneof, includes an expansible chamber 32, internal wall of which is in the form of a flexible diaphragm 33. The interior of chamber 32 is connected through a suitable conduit 34 with, the exterior of the hub at a point essentially in a'plane including the axes of blade shanks it. It is recognized that in the case of rotors having adjustable blades such as ships propellers, hydraulic turbine runners, pump impellers, or where such a rotor operates in any fluid, the external pressure at the up-stream end of the hub exceeds that of the rear or downstream end. By connecting the expansible chamber 32 to the exterior of the hub at a point where the average external pressure exists, the difference in pressure between the exterior and. interior of the hub is minimized, with the result that diaphragms 29 are not subjective to material pressure differences therein at the interior and exterior surfaces, with the increasing reduction in wear which would occur where these press 3 sure differences cause displacement of the diaphragm to an extent causing contact thereof with one or another of the relative movable surfaces between which they are disposed.

To seal the chamber within which the hub stmes are mounted, I provide a seal between the upper end wall I6 of hub l3 and the reciprocatory shaft 20. At the present this seal comprises a collar 35 which may be integral with or secured to shaft 20 and a diaphragm 36 sealed to this collar and to the upper end wall 1'6 of shell 15.

It is furthermore pointed out that in a construction of this sort where the hub is in a form of a sealed chamber and a reciprocating control for pitch variation is utilized, the capacity of this chamber will vary in accordance with the position of operating shaft 2! Expansible chamber 32 serves not only as a means for equalizing internal and external pressures as outlined above, but likewise as a means for compensating for this variation of internal capacity and to eliminate strains which would otherwise be placed upondiaphragms 29 and 35. All of the diaphragms 29, 33 and 3B are provided with circum. ferentially extending corrugations or are otherwise designed to permit the desired deflection. In the case of diaphragms 33 and 36, thepurpose of such corrugations will be readily understood, and in the case of diaphragms 29, as pointed out, these circumferential corrugations give to diaphragms 29 increased radial length which assists in reducing fatigue resulting from circumferential distortion.

Since the construction illustrated in the foregoing is purely an example of one method of producing my invention and the arrangement illustrated is obviously capable of considerable modification, I do not wish to be understood as limiting myself thereto, except as hereinafter claimed.'

I claim:

1. In an adjustably bladed rotor adapted to operate in a fluid medium, a hollow hub, blades having shanks mounted for oscillation in bearings in said hub, elastic diaphragms surroundingsaidshanks, said diaphragms being sealedat their peripheries to said hub and blade shanks,

said hub, a fluid lubricant in said hub, said hub including an interiorly disposed expansible'chamher the interior of which is in communication with the exterior of the hub in a zone of average pressure.

2. In an adjustably bladed rotor adapted to operate in a fluid medium, a hollo hub, a rotor shaft mounting said hub, blade having shanks mounted for oscillation in bearings in said hub, elastic diaphragms surrounding said shanks, said diaphragms being sealed at their peripheries to said hub and blade shanks, positioning means for said blades including a solid shaft extending through said rotor shaft and into said hub, means effecting a fluidtight seal between said positioning shaft and hub, operating connections between said positioning mean and blade shanks within said hub, a fluid lubricant in said hub and said ltioning means for said blades including a solid shaft extending into said hub, means effecting a 'fiuidtight seal between said positioning shaft and hub, operating connections between said po- 'sitioning means and blade shanks Within said hub, a fluid lubricant in said hub, said hub in- V eluding an interiorly disposed expansible chamher the interior of which is in communication with the exterior of the hub in a zone of average '1. pressure, the first named diaphragms being provided with ciroumferentially extending corrugations.

4. In an adjustably bladed rotor adapted to opcrate in a fluid'mediu'm, a hollow hub, a rotor shaft mounting said hub, blades having shanks mounted for oscillation in hearings in said hub, elastic diaphragms surrounding said shanks, said diaphragms being sealed at their peripheries to said hub and blade shanks, positioning means for said blades including a single shaft extending through said rotor shaft and into said hub, means efiecting a fluidtight seal between said positioning shaft and hub, operating connection between said positioning means and blade shanks within said'hub, a fluid lubricant in said hub and said hub including an interiorly disposed expansible chamber theinterior of which is in communication with the exterior'of the hub'in a zone of average pressure, the first named diaphragm being provided with circumferentially extending corrugations.

5, In an adjustably bladed rotor adapted to operate in a fluid medium, a hollow hub, a hollow shaft mounting said hub, blades having shanks mounted for oscillation in said hub, a reciprocating shaft extending through said hollow shaft and connected to the blade shank to oscillate the same, sealing means between said blade shanks and hub and between said'shaft and hub whereby to form the hub asa sealed lubricant receiving chamber, and an expansiblechamber having a movable wall within the hub and having its interior in communication with the exterior of the hub.

ROBERT E. B. SHARP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 734,468 McCollum July 21, 1903 1,510,086 Englesson Sept. 30, 1924 2,421,841 Lowy June 10, 1947 FOREIGN PATENTS Number Country Date 28,257 Denmark Aug. 15,1921

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