US 1901773 A
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Description (OCR text may contain errors)
March 14, 1933. A, PFAU 1,901,773
l PROPELLER BLADE ADJ US T I NG S YS TEM 2 Sheets-Sheet 2 Filed Aug. 22, 1931 l fm f 6 .il 7 am w lo 3 9 4 4 4 o 8 6 7 4 4 4 v Q, m .w ,Lwmol 1 I@I|.I6 .J /1 5 7/ /I 8 9 A1 ,d Y fw .w M. a@
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rAreNr ol-Flc-E 'l mmm, 0F MEWAUXEE, WISCONSIN, CORPORATION O F DELL- @RIOELLEB BME ABQTUSTHQG @Sm hupiieaten tiled August 2Q, 1931. 'Serial Eo. 558:38.
This invention relates in general to systems using electric motors For controlling the tilt of the rotor blades of propeller t hydraulic turbines, pumps, blowers, an -ot aircraft and marine pro ellers. Y
lt is hmown that the e ciency o hydraulic turbines et the propeller type can be increased when operating with row loads and low effective heads of water by adjusting the tilt of the rotor blades. rThe eciency of other machines having blades adapted to rotate in a duid medium may also. be increased by controlling the tilt of the blades in accordance with the operating conditions. Various mechanisms for tilting the rotor blades of hydraulic machines by means of a rod which is rotatable within a hollow shaft which is connected to the blade carrying hub have been devised, but certain of these mech anisms can only be adjusted after the machine has been shut down, and others have proven unsatisfactory from a practical operating standpoint. lt is obviously desirable that the tilt of the blade be adjustable during rotation thereot` in order to obviate the inconvenience of stopping the machine every time an adjustment of the blades is to be made.
An object of this invention is to provide a vadapted to be mounted within a portion of the shaft which transmits power to and from the propeller blades.
Another object of this invention is to provide a rotor blade tilting system in which the blades are tilted during running by a shaft which is rotatable wlthin the power transmitting shaft by a rotary servomotor.
Another object of this invention is to provide a propeller blade tilting system in which a rotary electric-servo-motor for tilting the blades is caused to rotate a number of revolutions proportional to the movement of a control switch.
further object of this invention is to provide a rotary servo-motor device for tilting propeller blades which is simple and compact in construction, efficient and dependable in operation, and inexpensive to manufacture.
propeller blade tilting servo-motor which is A These andother objects and Aadvantages are attained by this invention,'various novel features of which will be apparent from the description and drawings herein, and will be more particularly pointed out 'in the claims.
Various illustrative examples of the a. plication of this invention are shown in t e accompanying drawings, in which;
Figure 1 shows a system for controlling the tilt of the runner blades of a hydraulic turbine;
Fig. 2 is a vertical section of an electric servo-motor embodying features ofthe present invention;
Fig. S'is an enlarged vertical section of the limit switch operating reduction gearing' shown inFig. 2
` Fig. Il is a vertical section of a modified form of electric servo-motor embodying fea-Y tures of the present invention.
With the above objects in view, as well as other objects which will appear as the specification proceeds, the invention comprises a construction, arrangement, and combination of arts now to be fully described and hereinater claimed. It bein understood that the` disclosure herein described is merely illustrative of the invention and is not to be taken in a limiting sense, vchange in detail of construction and arrangement of parts being permissible so lon as within the spirit of the invention and e scope of the claims which follow.
Referring now to Figure 1, 10 is a. hydraulic turbine having adjustable guide venes 11, and a rotor hub member 12 to Y which tiltable blades 13 are connected. Any suitable mechanism within hub 12 for tilt- 90 ing blades 13 may be used, noting the patent to J. J. Ring, U. S. 1 656,017, and the patent to J. r. Roberts', U. s. 1,656,018, both issued on January 10, 1928, for typical showings of such mechanism. Movement of guide vanes 11 is eiiected by a servo-motor 19 which is operatively connected to the guide vanes 11 by means of `crank 18, a shaft 17, rod 16, and a guide vane adjusting ring 15. Valve 20 of servo-motor 19 is controlled by governor 21 in any known manner. The runner blades forward or reverse direction by the control mechanism of follow-u device 28, which in turn is controlled by t e dierential transmitter device having pulleys 31 and 33 which are rotated in accordance with the height of float 32 in the head water and the height of the float 34 in the tail water, respectively. The motion of guide vanes 11 is relayed to topographic cam 25 by means of linkage which comprises guide vane adjusting ring 15, rod 16, shaft 17, crank 22, link 23, and cam carriage 26. Cam member 25 is thus longitudinally movable in response to the position of the guide vanes.
No claim is broadly made herein to the above described hydraulic turbine controlled system comprising governor controlled guide vanes, a servo-motor for tilting the runner blades, a topographic cam device for controlling the blade tilting servo-motor in accordance with both the effective head of water and the position of the guide vanes, because this system constitutes the subject of a co- Eending application, Serial No. 552,639, filed y this same inventor on July 23, 1931.
Referring now to Fig. 2, the power transmitting shaft between the turbine and the generator is constructed in two sections, 47 and 51, having flange members 48 and 52, res ectively, which ,engage corresponding ange members 46 and 50 of a rotatable casing member 42, having covermember 44. A
stationary housing member 57 surrounds the casing member 42 and is supported from any suitable stationary structure such as the generator foundation asshown lin Figure 1, or the upper part of the 'turbine casing 10. Within the lower section of the power trans mittin shaft is located a rotor blade tilting `rod w ich is rotatable with respect to this shaft to'actuate the mechanism in hub member 12. The bladetilting rod 56`is rotated at slow speeds by an electric motor 53 by means of speed reduction gearing 55 of any suitable form. The motor 53 is mounted to casing 42 by any suitable means such as base member 54. Current is supplied to motor 53 by means of conductors 58, slip rings 59,
.brushes 62, brush holders 63, reversing switch 38 and conductors 68-69. It is to be noted that brush holders 63 are fastened to the sta.-
tionary casing 57 and are insulated therefrom by insulating members 64, and that slip rings 59 are insulated from the rotatable casing 42 by means of insulation 60 and 61.
Reversing switch 38 comprises stationa contacts and 66 and movable contact 6 which is suitably insulated from the contact pivot 70. Reversing switch 38 is normally held in the neutral position shown in Fig. 2 by means of a link 39 which connects contact 6 with floating lever 37. One end of iloatin lever 37 is actuated bycontrol rod 36 an cam follower member 35 in accordance with the altitude ofl cam 25. The other end of floating lever 37 is actuated in accordance with the position of the runner blades by means of mechanism which is responsive to the position of a gear member 7 9 threaded on the shaft of 71 as will be more fully described. Referring more particularly to Fig. 3, a threaded s aft- 71 is rotated in stationar guide bearings 72 by motor 53. A trave ing gear 79 having a bore provided with screw threads is threaded .on shaft 71. A pinion 74, which is fixed to shaft 71, drives a glear 75 which is xedto counter-shaft 76.' ounter-shaft 76 is suitably supported in bracket member 73 as byvr bearing 77. Bracket member 73 which carries bearings 72 and 77, is attached to the inner wall of casing 42. A inion 78 is also fixed on countershaft 76 an is sulicientl long to remain in engagement with the tcet of gear 79 as this gear travels on' threaded shaft 71. The gears and pinions are of such a ratio that gear 79 is driven by pinions 78 in the same di- 4 rection of rotation as shaft 71, but preferably at slightly less speed. It is thus seen that gear 79 will be caused to move transversely at a speed proportionalto the difference of the rotative speeds of the shaft 71 and the gear 79. Gear 79 is provided with a fixed collar 81 and a removable collar 82 which is held inplace by means of nut 83. l
Referring again to Fig. 2, a spider member 84 is carried by collars 81 and 82 and is provided with arms whichproject throu suitable slots in casing member 42. e ends of these arms are provided with shoe m'embers 85 which rest u n an annular thrust ring 86 which is attac ed to relay lever 41 by means of a pivot connection 87. It ia desirable in some instances to construct spider member 84 (and 84 in Fig. 4) in two parts to expedite the assembling of the eervo- A motor. It will thus be seen that the ri t hand end. of floating lever 37 is actuated link 40 and relay lever 41 in accordance wi the number of revolutions vof motor 53 fromv an given position.
eferring now to Fig. 4, the servo-motor shown in this' figure is substantially the same as that shown in Figs. 2 and 3, exce t that the annular thrust rin 86 is actuated y a spider member A84 whic is threaded d1- rectly onto the blade tilting rod 56 instead of being actuated by a spider member which is drivenolylrauxiliary differential gearin In this m cation the pitch of the threa 88 on shaft 56 are so chosen that for a full ran movement of -the rotor blades the spi er member S4 will be moved from one end of chamber 89 to the other end thereof. a The'operation of the propeller blade adyusting lsystem is as follows:
Upon movement of topogra hic cam member in response either to a ange in guide vane opening or a change in elective head of water, cam follower will raise or lower contact 67 a predetermined amount thereby establishing a circuit for motor 53 from supply conductors 68-69 through either contact 66 or depending on the direction of motion of cam follower 35. Motor 53 in rotating drives rotor blade tilting shaft 56 through reduction gears 55 and also moves spider member 84 (or 84 as in Fig. 4) in such a direction as to restore movable contact 67 to its initial od position after the motor has rotated a number of revolutions proportional to the amount of movement of switch contact 67. The ron tation oi rod 56 relative to power transmit ting shaft 51 changes the tilt of the propeller blades 13 by means of the mechanism in hub l2. When switch contact 67 is returned to its o position the motor 53 is deenergized and rotor blades 13 remain in their newly adjusted osition until the operating conditions again c ange.
While the embodiment of the invention herein described relates more in particular to hydraulic turbines, the invention is obviously ap licable to impeller type pumps, blowers an to aircraft and marine ropellers an it is therefore desired that t e term propeller be considered descriptive of such mechanism. lt is to be noted that if the ratios of gears 7l, 75, 78, and 79 are such that gear 7 9 is rotated faster than shaft 7l, spider member 84 can be made to operate in a direction opposite to what it would rotate ii the gear ratios were such that gear 79 rotated slower than shaft 7 l.
llt is to be understood that the disclosure herein described is merely illustrative ci the invention and is not to be taken in a limiting sense, changes in details ci' construction and arrangement ci parts being permissible so long as within the spirit oi the invention and the scope oi the claims which follow.
lt is claimed and desired to secure by lietters Patent:
l. lin combination, a pro eller shait, tiltable propeller blades carri by said shaft, a rod for tilting said propeller blades, means including an electric motor ier operating said blade tilting rod, a control switch mov` able from a neutral position to control the energization and direction ci rotation of said motor, and means includin a traveling not member on said motor shaft or restoring said switch to said neutral position.
2. ln a servo-motor for controlling the tilt of propeller blades, the combination of a rotatable shaft, a housing attached to said shaft, an operatin rod extending longitudinally of said sha ,an electric motor within said housing, a speed reduction gearin connected between said electric motor an said operating rod, means includin sliprings and a reversing switch for con uctin current to said motor, means for moving sai reversing switch a predetermined amount to cause said motor to rotate, and means including speed reduction caring driven by said motor for stopping said motor after said motor has rotated an amount proportional to the said predetermined movement of said reversing switch. A
3. ln a servo-motor for controlling the tilt of propeller blades, the combination of a rotatable shaft, a housing attached to said shaft, a blade tilting rod extending co-axially of said shaft, an electric motor within said housing, a reversing switch for controlling the direction of rotation of said motor, a threaded shaft driven by said motor, a pinion fixed to said threaded shaft, a counter-shaft driven by said pinion, an elongated pinion fastened to said counter-shaft, a gear having an internally threaded bore and mounted on said threaded shaft whereby said gear is driven by said elongated pinion in the same direction as said threaded shaft, and means for movingsaid reversing switch in response to the amai movement of said gear.
6l. in a servo-motor for positioning a movable element, the combination of an electric motor, a normally open switch for controlling the energization of said motor, means for moving said switch a predetermined amount to start said motor, a threaded shaft driven by said motor, a member having an internall threaded ,bore engaging said threaded shaft, means for rotating said member in the same direction as the rotation of said motor but at a diderent speed, to cause said member to move axially of said threaded shaft, and means for causing said switch to move toward its open position in response to the axial movement oi said member whereby said motor is operative to rotate a number oi revolutions proportional to the amount of said predetermined movement of said switch.
5. ln a servo-motor for positioning a mov-s able element, the combination of an electric motor, a switch for controlling the energize tion of said motor and having an oid position, means `for moving said switch from said oid position a predetermined amount to operate said motor, a threaded shaft driven by said motor, a gear having an internally threaded bore rotatably carried by said threaded shaft, means including a pinion and a counter-shaft for rotating said gear at a speed proportional to the speed oi the motor but not equal thereto to axially move sa1d gear, and means responsive to the motion of said r for returning said switch to its o position to stop said motor.
Y 6. In a servo-motor control system, the
combination of an electric motor, a switch for starting and stopping said motor, a gear having an internally threaded bore, a threaded shaft extending through said bore and driven by said motor a pinion on said threaded shaft, a counterha t driven by said pinion a pinion on said counter-shaft for driving said gear, whereby said gear is moved axially proportionallyto the algebraic sum ofthe speed of said threaded shaft and the speedo movement of said arms, and means for moving said switch in accordance with the movement of said ring-member.
8. In combination, a ower .transmittin shaft, tiltable propeller b adescarried by sai shaft, a housing member attached to said shaft intermediate its ends, speed reduction caring and an electric motor within said ousing, means including a rod co-axial of said shaft forvcausing said motor to rotatel said rod through said gearing `to tilt said blades, a switch for controlling said motor, and a traveling nut member on said rod for controlling said switch.
9. In 'a system for controlling the tilt of the pro ller blades of a hydraulic turbine, the com ination of a rotatable propeller shaft, an electric motor and gearing carried by said propeller blade tilting rod operatively connected to said motor throu h said gearing, a reversing-switch for controlling` the direction and amount of rotation of said motor, said switch having a neutral position, Ameans for actuating said reversing switch from said neutral position in response to an operating condition of said turbine, and means actuated in accordance with the movement of said blade tilting rod for returning said reversing switch to said neutral position, said last mentioned means comprising a spider member rotatable with said propeller shaft and a nonrotatable ring member slidably engaging said spider member.
10. In a system for controlling the tilt of propeller blades, the combination of a rotatable propeller shaft, a hollow casing attached to said pro ller shaft, an electric motor mounted wit in said hollow casing, a propeller blade tilting rod coaxial of said propeller shaft, gearing arranged between said electric motor and sald blade tilting rod for rotating said rod relative to said pro ller shaft, a spider member rotatable wit said hollow c amber, means for movingsaid spider member axially of said rod in accordance with the rotation of said rod by said motor, shoe members carried bysaid spider member, a ring member slidably engaging said shoe members, a lever member for holding s aid ring member in engagement with said shoe members, a stationary pivot for said lever member, a reversing switch for controlling the direction of rotation offsaid motor, and means for automatically actuating said reversing switch including a relay connection between said lever and said reversing switch.
11. In a system for automatically controlling the tilt of the propeller blades of a hydraulic turbine, the combination of a rotatable ro eller shaft, a hollow casing attached to said s aft, an electric motor and speed reduction gearing mounted within said hollow casing, a propeller blade tilting rod operatively connected to said motorfthrough said gearlng, a reversing switch for controlling the direction and duration of rotation of said motor, means for actuating said reversing switch in response to operating conditions of said turbine, said means compising a topographic cam member movable in accordance with said conditions, and means for relaying the movement of said blade tilting rod to said reversing switch.
12. In a system for automatically controlling the tilt of the propeller blades of a hydraulic turbine, the combination of a rotatable pro ller shafta hollow casing attached to said `s aft, an electric motor and speed reduction gearing mounted within said hollow casing, a propeller blade tilting rod operatively connected to said motor through said gearing, a reversing switch for controlling the direction and duration of rotation of said motor, a ioating lever operatively connected intermediate its ends to said reversing switch, means for actuating one end of said floating lever in response to an operating condition of said turbine, and means for actuating the other end of said ioating lever in accordance with the movement of said blade tilting rod. r
13. In a system for automatically controlling the tilt of the propeller blades of a hydraulic turbine, the combination of a rotatable propeller shaft, an electric motor and gearing carried by said rotatable shaft, a prov peller blade tilting rod operatively connected to said motor through said gearing, a reversing switch for controlling the direction and duration of rotation of said motor, said switch having stationary contacts and a movable contact member operable from a neutral position to selectively engage said stationary contacts, a Boating lever operatively connected at a )pointintermediate the ends thereof to said movable member, means for actuating one end of said floating lever in response to 5 an operating condition of said turbine, and means for actuating the other end of said Hoating lever in accordance with the movement of said blade tilting rod so as to move rsaid contact member toward said neutral pow 'sition.
In testimony whereof, the signature of the inventor is aiiixed hereto.