US2035689A

US2035689A - Governing apparatus

Info

Publication number: US2035689A
Application number: US728257A
Authority: US
Inventors: Ozro N Bryant
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1934-05-31
Filing date: 1934-05-31
Publication date: 1936-03-31
Anticipated expiration: 1953-03-31

Description

March 31, O. N BRYANT GOVERNING APPARATUS Filed May 51, 1934 ATTORNEY VNVENTOR OZRO N.BRYF\NT.

BY I

Patented Mar. 31, 1936 GOVERNING APPARATUS Ozro N. Bryant, Prospect Park, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of ?ennsylvania Appiication May 31, 1934, Serial No. 728,257

5 Claims.

My invention relates to pressure developing means of the type particularly suitable for use in fluid-pressure governing apparatus and it has for an object to provide pressure developing means which shall be economical in the consumption of power.

In fluid-pressure governing apparatus having impellers for developing pressure for governing, it has been found that excessive power consumption may be involved, particularly in connection with the governor impeller. In accordance with the present invention, instead of the pressure range for governing or control purposes being afforded by an impeller device of special design to give a governing pressure range, the pressure range is aliorded by a centrifugal escape device. In other words, I provide a source of fluid under pressure, which may be provided by an ordinary centrifugal pump, the magnitude of the pressure or changes in which are immaterial so long as the pressure is sufficiently high, and pressure from such source is supplied through an orifice to a passage, the passage furnishing fluid under pressure to suitable pressure-responsive means and the other end of the passage having a centrifugal escape device in communication therewith, the escape device functioning to modify the pressure in the passage so that such pressure varies substantially as the square of the speed of the turbine. Accordingly, a further object of my invention is to provide apparatus of this character having these advantageous features of construction and of operation.

A further object of my invention is to provide pressure developing means wherein fluid is supplied from a suitable source through an orifice to a passage, the passage communicating with suitable pressure responsive means and having the pressure therein controlled by a suitable centrifugal resistance arrangement.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

-Fig. 1 shows a side elevational view of a turbine with my improved pressure-developing means for the governing apparatus thereof applied thereto; and

'Fig. 2 is a detail View of a modified form of pressure developing means.

"Referring now to the drawing more in detail, in Fig. 1, I show a turbine including a stator structure Hi and a rotor II. The admission of elastic fluid to the turbine is controlled by a suitable admission valve l2, operated by servo-motor apparatus, at l3, controlled by a pressure-responsive device It. The apparatus so far described is conventional and needs no further description, it being merely necessary to bear in mind that the pressure-responsive device I i acts in response to pressure change in one direction to move the admission valve in one direction and vice versa.

The pressure-responsive device M is supplied with fluid under pressure by a passage it, such passage having fluid supplied thereto from a suitable source through an orifice and variation of pressure therein being secured by an escape device which functions to set up resistance to escape varying as a function of the turbine speed.

More particularly, I show the passage l5 extending into the stator structure and communicating with an annular chamber It formed between the interior of the axial bore ll of the stator structure and the rotor i l. The stator structure also has formed therein an impeller chamber l 8. An impeller i9 is arranged-in the impeller chamber and is carried by the rotor H, the impeller having an eye 26, supplied from the fluid pressure supply 2 l.

Fluid under pressure from the impeller chamber i8 is supplied through the orifice 23 to the passage l5. Means, for example, spaced packing rings E i, are carried internally of the bore I1 and cooperate with the rotor H to define the aforesaid annular chamber 56, the latter preferably including an annular channel 25 formed in the stator structure It. The rotor of Fig. 1 is formed with a transversely extending and inclined passage 27, one end of the latter communicating with the annular chamber i6 and the other end communicating with the drain space 28.

Assuming that the rotor is rotating, it will be apparent that the column of liquid from the axis to the end of the inclined passage 2'! which communicates with the annular chamber It sets up resistance to escape, that is, a head of liquid is developed, due to centrifugal force, which resists escape from the annular chamber. In other words, the inclined passage provides for a pressure in the supply passage l5 which varies as the square of the diameter of the portion of the rotor having such inclined Passage, as the density or specific gravity of the liquid, and as the square r of the speed of the rotor.

As already pointed out, the pressure developed in the impeller chamber is immaterial so long as it is above the operating pressure in the passage l5. Any excess flow above that required for governing escapes through the inclined passage 2?.

The flow through the orifice 23 varies as the square root of the pressure difference thereacross. Perhaps certain figures, given by way of example, may make the flow operation somewhat clearer. Assuming that the impeller pressure is 90 pounds and that the pressure in the line I5, which depends upon the rotor diameter, liquid density, and the square of the rotor speed, is 40 pounds the flow through the orifice would vary as the square root of 50, that is 7; and, if the impeller pressure is reduced to '70 pounds, the supply pressure still remaining at 40 pounds, then the fiow would be the square root of 30 or 1 the escapes under the two conditions being in the ratio of seven to five and one-half.

From the apparatus so far described, it will be apparent that the diameter of the rotor in the vicinity of the centrifugal escape device is important where centrifugal head of fluid is depended upon to afiord the resistance to escape, it being borne in mind that the pressure in the governor passage I5 varies directly as the square of the diameter of the rotor and directly as the square of the speed thereof. Accordingly, I show the spindle modified to provide for variation in the diameter of the portion thereof cooperating with the pressure developing means. To this end, knowing the speed of the turbine and the desired pressure, a bore ll of suitable diameteris provided and the spindle H has an annular member 29 fixed thereto, the member 29 being of the desired diameter and the passage 2'! being formed both in the member 29 and in the rotor structure proper. Assuming that a pressure of 40 pounds of a given governing oil is desired in the governing passage [5, then, for a speed of 3600 R. P. M., if a shaft diameter of 5 inches is required, for a speed of 1800 R. P. M., a shaft diameter of inches would be required, and, for a speed of 900 R. P. M., a shaft diameter of 20 inches would be required.

From the figures last referred to, it will be apparent that if the turbine is of small size and the speed is low, the diameter of the centrifugal escape device may be excessive. Accordingly, in Fig. 2, I show means which is essentially the same in principle as that shown in Fig. 1 except that means is provided for increasing the mass factor of the centrifugal resistance. In Fig. 1, as already pointed out, this resistance is afforded by the head of liquid between the rotor axis and the end of the inclined passage communicating with the annular chamber 25. In Fig. 2, instead of relying upon the centrifugal head of liquid, I provide the spindle H with one or more radial passages 3| communicating with the annular chamber H5 and each passage having a valve seat 32 at its end. A ball valve 33 cooperates with each seat 32, and it will be apparent that the centrifugal resistance to escape of fiuid from the annular chamber 25 and through the passage or passages 3|, is dependent upon size and the density or specific gravity of the ball or balls 33. By using balls made of heavier or lighter materials, or varying the size thereof, it will be apparent that the diameter of the portionof the rotor pro vided with the centrifugal escape device may be" made independent of the turbine speed and rotor or spindle size.

WhileI have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In control mechanism, a pressure responsive device, a stator structure having an axial bore, a rotary member extending into the bore, means carried by the stator structure and cooperating with the rotary member to provide an annular chamber, a source of fiuid under pressure, a passage for supplying fluid under pressure to the pressure responsive device and communicating with said annular chamber, an orifice for supplying fiuid from said source to the passage, and a diagonal passage extending transversely of the rotary member, one end of said diagonal passage communicating with the annular chamber and the other end communicating with exhaust space.

2. The combination with a prime mover having a rotor, motive fluid admission means, of a governor controlling the admission means, said governor including a passage for liquid under pressure, means responsive to pressure in said passage for controlling the admission means, escape means for the passage and operating in response to speed of the rotor to provide pressure in said passage varying as a function of the rotor speed, means operated by the rotor for developing liquid under pressure which is greaterthan the passage pressure, and an orifice for supplying liquid from the last-named means to the passage, whereby said passage is maintained filled with liquid from the orifice at a pressure determined by the escape device and excess liquid supplied to the passage from the orifice fiows through the escape device without affecting the pressure in the passage.

3. The combination with a prime mover having motive fluid admission means, of a governor controlling the admission means, said governor including a passage for liquid under pressure, means responsive to pressure in said passage for controlling the admission means, a rotor construction operated by the prime mover, means including the rotor construction providing an annular chamber forming a part of the passage, escape means carried by the rotor construction and communicating with said chamber and utilizing centrifugal force due to rotation of the rotor construction for providing resistance to escape of liquid from the passage varying as a function of the speed of the rotor construction, means operated by the prime mover for developing liquid under pressure which is greater than the passage pressure, and an orifice for supplying liquid from the last-named means to the passage, whereby said passage is maintained filled with liquid from the orifice and at a pressure determined by the escape means and excess liquid entering the passage from the orifice flowing through the escape means without affecting the pressure in the passage.

4. The combination with a prime mover having motive fiuid admission means, of a governor con trolling the admission means, said governor'including a pressure responsive device operatively connected to the admission means, a passage for supplying liquid under pressure to the pressure responsive device, stationary structure having a cylindrical bore, a rotor construction operated by the prime mover and having a portion extending through the bore, spaced sealing means carried by the stationary structure internally of the bore and cooperating with said portion of the rotor construction to define an annular chamber forming a part of said passage, escape means carried by the rotor construction and communicating with the annular chamber and utilizing centrifugal force due to rotation of the rotor construction to afford resistance to escape of liquid from the passage varying as a function of the speed of the rotor construction, means operated by the rotor construction for developing liquid under pressure which is greater than the passage pressure, and an orifice for supplying liquid from the last-named means to the passage, whereby said passage is maintained filled from the orifice and at a pressure determined by the escape means and excess liquid entering the passage from the orifice flowing through the escape means without afiecting the pressure in the passage.

5. The combination with a prime mover having motive fluid admission means, of a governor controlling the admission means, said governor including a passage for liquid under pressure, means responsive to pressure in the passage for controlling the admission means, means providing an annular chamber forming a part of said passage, a rotor construction operated by a prime mover, escape means carried by the rotor construction and communicating with the annular chamber and utilizing centrifugal force due to rotation of the rotor construction for afiording resistance to escape of liquid from the annular chamber varying as a function of the speed of the rotor construction, an impeller carried by the rotor construction, an impeller chamber enclosing the impeller, said impeller being constructed and arranged to provide liquid under pressure which exceeds the pressure in said passage, and an orifice for supplying liquid from the impeller chamber to the passage, whereby said passage is maintained filled from the orifice and at a pressure determined by the escape means and excess liquid entering the passage from the orifice flowing through the escape means without aiiecting the pressure in the passage.

OZRO N. BRYANT.