US2426045A

US2426045A - Rotor governor

Info

Publication number: US2426045A
Authority: US
Inventors: Rudolph F Onsrud
Original assignee: ONSRUD MACHINE WORKS Inc
Current assignee: ONSRUD MACHINE WORKS Inc
Priority date: 1945-08-25
Filing date: 1945-08-25
Publication date: 1947-08-19
Anticipated expiration: 1964-08-19

Description

All@ 19, 1947. RT F. oNsFUD I 2,426,045 v RoTR GQvERNoR yFiled Aug. 25, 1945 2 Sheets-Sheet l 2 Sheets-Sheet 2 Aug', 19, 1947.Y R. F. oNsRuD I ROTOR GOVERNOR Filed Aug. 25, 1945 .1 il I/ il `26 /0/ I fav ii 27 1 i 2.5

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f7 /a f6 i br/Weys Patented Aug. 19, i947 RTGR GOVERNOR Rudolph F. Onsrud, Chicago, Ill., assign'or to Onsrud Machine Works, Inc., Chicago, Ill., a corporation of Illinois Application August 25, 1945-, Serial No. 612,572

6 Claims.

In fluid-driven motors, principally of turbine type and especially where high speeds are concerned, there is no known means of automatically adjusting the uid input to fluctuating loads. The use of fly weights, springs, etc., on a rotating member for governing the speed thereof is impractical for high speeds because of the connections that must be made with a stationary part. Such connection is subject to exceptional frictional heat resulting in a rapid wearing away of the materials and thereby spoiling the adjustment. Because of the high speed of a turbine rotor-say for example, five miles per minuteany rotating exible device for governing speeds becomes rigid and inilexible inthe speed range in which the automatic adjustment is necessary.

The device of the present disclosure makes use of the fact that a high speed rotating wheel is expanded radially to some degree by centrifugal force proportionately to its speed of rotation and utilizes this expansion to control a throttle valve in the power medium supply for governing such speed.

The main objects, therefore, of the present invention are to provide an improved form of governor for high speed rotation; to provide improved means senitive to the centrifugal expansion of the rotating part for controlling a uid-driven mechanism; to provide an improved form of centrifugally actuated governor for controlling the fluid delivery nozzle of a turbine; and to provide improved throttle-valve actuating mechanism for devices of this kind.

A further object is to provide an improved mechanism for controlling the power supply to a Huid-pressure driven machine, by means which senses the location of a relatively moving surface without having physical Contact with such surface.

A specific embodiment of the present invention is illustrated in the accompanying drawings in which:

Figure 1 is a plan View of a speed governing device made in accordance with this invention for controlling the speed of a vertical spindle driven by a horizontally disposed turbine wheel using air under pressure as the source of power.

Fig. 2 is a vertical sectiony of the same taken generally ony the line 2-2 of Fig. 1 but deviating slightly from the plane of said line in order to include in the view certain parts lying at one side of that plane.

Fig. 3 isa lvertical section taken at rightangles to the plane of sectionvof Fig. 2 on the irregular line 3%' of Fig. 1.

2 Fig. 4 is a sectional detail taken onthel-line liof Fig. 2.

In the form'shownin the drawings, the turbine- Wheel or rotor I is fastv on a spindle 2cairied by ball Vbearings 3" andhas formed ir` its rim portion l the usual annular series of bucke'tblades 5. The periphery 6 is of smoothvcylindrical form and the rotor is made of suitable material; 'such as an aluminum alloy whereby', when driven-at the high speeds of such turbine rotors, it'sperifph'- ery would have a perceptible a-mountvofeiipan' sion Whichrv'aries with the speed of rotation ofthe rotor.

The housing l has a iluid dischargen'ozzle 8 positionedY so as to direct a jet of" iluid against the buckets 5 for drivingv the; rotor. 'I-'he housing also `has an appropriate exhaust outlet 9"-at the" opposite side of the buckets.

Fluidy under pressure, in this vcase yair', is` supe' plied to the nozzle 8f by a pipellll whichis conI nected to. the inlet duct l and haslthe usual stop valve (not shown) for admitting andE cutting off the supply of fluid to the nozzle 81 The governing'- device comprises ahous'in'g' ll formedY integrally with the rotor Vhousing and*y havingv a cylindrical bore or chamber flf2`*ir1'` axial alinement with the nozzle 8. The outletv pas-'- sage LS leading frrom the chamberV l2" tothe nozzle 8- is.y tapered and has `r'n'ounted therein a needle valve h3 which is controlled and guided in its movements byany actuator l5" which is slid--A ably mounted'v in the chamber l2 to control; the discharge at said nozzle.

In the form shown, the actuator is inthe nature of a freely movable piston andcomprisesv a stem for the needle valve I4 of. less diameter than the diameter of the chamber I2` so as to provide a passage l5 for the free `flow offluid from the inlet passage l0 to the outlet passage i3. end of the actuator '|15A adjacent the -out-le't I23 is tapered and provided with spider arms -l'l between which there are openings -I8- for the passage of fluid.

The opposite end of the actuator I5 has apiston head` i9 and there is a by-passY duct 20" 'formed' in orlat one side of the periphery of 'this pis-ton to permit a small amount ofr iluid to-irassl into the part of the chamber l2 which is beyond the end of` the piston 19. The actuator issoar- :rangedi that it is highly sensi-tive to theel-differ; ence in Vpressures between` the two-sides of the piston l?)V and is ofsuch-length that the'passage' l 6 will at' all 'times-bei in: free.'communicationwiththe inlet 16,.' reg-ardlessof the position ofthepiston i9. The ifa'ceof the' piston Awhichcarriesl the needle valve I4 is of less effective area than its other face so that the piston will close the valve when both faces are exposed to the same pressure.

A bleeder pipe 2l, of small diameter but of greater area than the by-pass in the piston, is connected into the chamber I2 adjacent the cylinder head 22 and extends to a point Where the rim of the outlet 23 at its end is directly opposed to the periphery 6 of the turbine wheel. A tapered pin 24 threaded at 25 into the housing and having a knurled head 26 and lock nut 2'I provides for micrometrical adjustment of the space between the outlet end 23 of the bleeder pipe 2| and the periphery B of the turbine rotor I. To this same end, the pipe 2l should be of resilient material so that it normally bears outward against the pin 24.

The operation of the device shown is as follows:

When the fluid inlet valve (not shown) is opened and the fluid supply is admitted to the inlet I0, the piston I9 will be forced backward by the pressure of the fluid and the nozzle 8 will be open for maximum flow of air to the turbine.

So long as the gap between the outlet 23 of the tube 2l and the periphery of the rotor 6 is sufciently large to allow the escape of air at this point to the full capacity of the bleeder passage 20 in the piston I9, the piston will remain at the backward limit of its stroke and as the speed of the turbine wheel increases centrifugal expansion of its periphery 6 tends to close the gap at the outlet 23.

When this gap is such that its capacity is less than that of the by-pass 20, then pressure will build up behind the piston I9 in the chamber I2 and the piston will be forced forward causing the valve I4 to partly or wholly cut ol the supply of air at the nozzle 8. This movement of the valve can be so balanced that a small fraction of .001 inch of variation in the gap will cause the plunger to move forward or back.

The micrometrical adjusting screw 24 regulates this gap and thus determines the maximum and minimum consumption of iluid relative to speed range.

This governor also acts as a safety device to partly or totally shut off air in the event of overrunning. Overexpansion of the rotor would entirely close the by-pass, force the needle valve forward and choke the nozzle orice to the limit provided for.

In the form shown, Variation in the gap at the outlet 23 is produced by radial expansion of the rim of the turbine rotor, but it is apparent that other elements of the machine, more or less responsive to centrifugal force, might provide the surface that controls the bleeder outlet, and that the changes in such surface might arise from other causes.

Although but one specic embodiment of this invention has been herein shown and described, it will be understood that numerous details of the structure shown may be altered or omitted without departing from the spirit of the invention as dened by the following claims.

I claim:

1. A governor, comprising a wheel having a smooth periphery, fluid-driven means for rotating said wheel at speeds that subject the wheel to centrifugal expansion, and huid-pressure supply means comprising a power supply passage for said iuid-driven means, a bleeder passage having its outlet opposed to the periphery of 4 said wheel for control by the radial expansion and contraction of said wheel, a throttle valve controlling the fluid flow in said power supply passage, and means for adjusting said throttle valve through changes in the relative pressures in said iuid-supply and bleeder passages.

2. A governor, comprising a wheel having a smooth periphery, fluid-driven means for rotating said wheel at speeds that subject the wheel to centrifugal expansion, and fluid-pressure supply means comprising a power supply passage for said fluid-driven means, a bleeder passage having its outlet opposed to the periphery of said wheel for control by the radial expansion and contraction of said wheel, a needle throttle valve controlling the fluid flow in said power supply passage, and means for adjusting said throttle valve through changes in the relative pressures in said huid-supply and bleeder passages.

3. A governor, comprising a wheel having a smooth periphery, fluid-driven means for rotating said wheel at speeds that subject the wheel to centrifugal expansion, and fluid-pressure supply means comprising a fluid supply passage for said fluid-driven means, a bleeder passage having its outlet opposed to the periphery of said wheel for control by the radial expansion and contraction of said wheel, a throttle valve controlling the fluid flow in said power supply passage, and means for adjusting said throttle valve comprising a balanced member actuated by changes in the relative pressures in said fluidsupply and bleeder passages.

4. A governor, comprising a wheel having a smooth periphery, fluid-driven means for rotating said wheel at speeds that subject the wheel to centrifugal expansion, and fluid-pressure supply means comprising a power supply passage for said iiuid-driven means, a bleeder passage having its outlet opposed to the periphery of said wheel for control by the radial expansion and contraction of said wheel, a throttle valve controlling the fluid ow in said power supply passage, means for adjusting said throttle valve through changes in the relative pressures in said iluidsupply and bleeder passages, and micrometrical adjustment means for setting said bleeder pipe outlet toward and away from said wheel,

5. The combination with a turbine rotor having a smooth periphery, and a nozzle for directing driving fluid to said rotor, of a governor comprising a throttle valve controlling said nozzle, a driving fluid supply chamber for said nozzle, an actuator for said throttle valve movable in said chamber and normally urged to open said valve by fluid pressure in said chamber, means for by-passing iluid behind said actuator, and a bleeder duct for such by-passed fluid having its outlet opposed to the periphery of said rotor, whereby the escape of iluid from said bleeder duct is controlled by the expansion and contraction of said turbine rotor.

6. The combination with a turbine rotor having a smooth periphery, and a nozzle for directing driving uid to said rotor, of a governor comprising a throttle valve controlling said nozzle, a driving uid supply chamber for said nozzle, an actuator for said throttle valve movable in said chamber and normally urged to open said valve by fluid pressure in said chamber, means for by-passing fluid behind said actuator, a bleeder duct for such by-passed fluid having its outlet opposed to the periphery of said rotor, whereby the escape of fluid from said bleeder duct is controlled by the expansion and contraction of said turbine rotor, and means for adjusting said bleeder outlet with respect to said file of this patent:

UNITED STATES PATENTS rotor. Number Name Date RUDOLPH F ONSRUD- 1,312,253 Johnson Aug. 5, 1919 REFERENCES CITED 5 1,460,746 Carlstedt July 3, 1923 1,917,092 Bristol July 4, 1933 The followmg references are of record 1n the 2 158 478 Parker May 16 1939