US2890877A - Governor - Google Patents

Description

June l6, 1959 D. A. STRAZNICKAS 2,890,877

GOVERNOR Filed on. '19, 1.955 2 Sheets-Sheet 1 IN VEN TOR.

June 16,1959 D. A. STRAZNICKAS 2,890,877

. GOVERNOR Filed 001;. 19, 1955 2 Sheets-Sheet z Q 52 53 v 5Q 55 J H 22 I I 1 I IN V EN TOR.

1 04 fl nald @52761 mckae, 102 I 0 BY GOVERNOR Donald A. Straznickas, Rockford, Ill., assignor to Sundstrand Machine Tool Co., a corporation of Illinois Application October 19, 1955, Serial No. 541,459 Claims. (Cl. 264-8) This invention relates to a governor, and. more particularly to a centrifugal-type governor.

It is the general object of the present invention to produce a new and improved governor.

It is a more specific object of the present invention to produce a centrifugal-type governor provided with means for varying the e'ifectiveness of the flyweights thereof in order to provide an extremely sensitive control.

Yet another object of the invention is to produce a governor having a rotatable flyweight wherein electromagnetic means are used to exert forces on the flyweight in addition with or in opposition to the centrifugal force acting upon the flyweight, and thus to vary the governing effect thereof.

Other and further objects and advantages of the invention will be readily apparent from the following description and drawings, in which:

Fig. 1 is a. vertical staggered section through a governor embodying the present invention;

Fig. 2 is a horizontal section along line 22 of Fig. 1; and

Fig. 3 is a view similar to the upper portion of Fig. 1 showing a modified form of construction.

While this invention is susceptible of embodiments in many diflferent forms, there is shown in the drawings and will herein be described in detail several embodiments, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated. The scope of the invention will be pointed out in the appended claims.

While it will be readily apparent to those skilled in the art that the advantages of the present invention can be utilized in many branches of the field of governor control, the specific embodiments of the invention illustrated in the drawings show contructions particularly adaptable for use in the governor control for a driven device,such as the governor control illustrated in the copending application of Sadler, et al., filed December 4, 1951 as Serial Number 259,872, now Patent No. 2,803,- 112. As illustrated in that application, a governor is utilized to direct hydraulic control fluid under pressure to a hydraulic piston and cylinder device for controlling the output of a hydraulic pump, the output of which is utilized to drive a hydraulic motor whose speed is to be governed.

As shown in Fig. l, the present invention is embodied in a centrifugal-type governor including a casing having a cylindrical bore 11 therein in which is fixed a ported sleeve 12. A pin 13 serves to prevent relative movement between the sleeve and casing, with the sleeve forming a support for a drive sleeve 14 which extends therethrough and is rotatable therein. The drive sleeve 14 is secured by means of a pin 15 to a drive shaft 16 extended exteriorly of the casing 10 and provided with a spline 17 to be rotated in accordance with the speed of rotation of the device to be governed.

The casing 10 is provided with a port 20 connected United States Patent 0;

2,890,877 Patented June 16, 1959 to a source of fluid under pressure and with a pair of ports 21 and 22 connected to opposite ends of a fluid pressure operated device. The ports 20-22 connect with passages 23, 24 and 25 respectively formed in the lower portion of the casing 10, with each of said passages terminating respectively in annular grooves 26, 27 and 28 formed in the fixed sleeve 12. The drive sleeve 14 is provided with three ports, 29, 3t) and 31, communicating respectively with the annular grooves 26, 27 and 28, and said ports are controlled by a pilot valve 35 reciprocable within the hollow of the drive sleeve.

The pilot valve 35 is provided with an operating stem 36 and spaced lands 37 and 38 separated by an intervening reduced portion 39. The stem 36 is provided with radial passages 40, each connected with an axial passage 41 in the stern, in turn connected with radial passages 42 in the upper portion of the stem, which latter passages open into a flyweight chamber 43 provided in the casing. A. suitable drain (not shown) from the chamber 43 is provided. The lower portion of the stem is open as indicated at 44, with the opening communicating with the axial passage 41 as illustrated. Suitable passages, not shown, are provided to connect area 44 with the chamber 43 so that no net pressure differential will exist between the top and bottom of the stem.

The pilot valve 35, when in the position illustrated in Fig. 1, is in neutral and the ports 34 and 31 are covered by the lands 37 and 38. It is clear that upward movement of the pilot valve will open the port 39 to control pressure from the port 29 while simultaneously connecting port 31 with the lower portion of the sleeve, and hence with the drain through the open end 44 and the passage 41 in the stem. Conversely, downward movement of the pilot valve will connect the port 31 with the pressure port 29, while connecting the port 30 with the drain through the radial passages 40 and axial passage 41.

To efiect' movement of the pilot valve, there is provided a centrifugal governor 50 including a. cup-shaped member 51 fixed to the upper end of the drive sleeve 14. A cage 52 is formed integrally with the drive sleeve and supports pivot pins 53, upon which flyweights 54 are mounted. The member 51 is merely a cylindrical cover which is used to keep the pivot pins 53 from falling out and to restrain the flyweights 54 from pivoting outwardly far enough to contact the interior of the casing. The flyweights 54 are generally L-shaped, and each are provided with an inwardly extended leg portion 55 positioned under a bearing 56 whose inner race issecured to the upper end of the stem 35. By this arrangement, outward pivotal movement of the upper ends of the flyweights serves to move the inwardly extending legs 55 upwardly, and hence move the valve stem and pilot valve upwardly to eifect control. The centrifugal action of the flyweights just described is opposed by the bias of a spring 60 which seats at its upper end on an adjustment bolt 61 threadedly received in. the casing and rotatable to adjust the tension of the spring. The opposite end of the spring 60 seats in a cupshaped member 62 supported by the inner race of the bearing 56, and thus transmits the spring force to the stern of the pilot valve.

It will be clear that in the operation of the governor so far described, changes in rotational speed of the shaft 16 will cause a corresponding pivoting action of the flyweights 54, outwardly if the speed increases, and inwardly if the speed decreases. Such pivotal movement of the flyweights is transmitted into valving movement of the pilot valve 35, resulting in the direction of control fluid under pressure to one end of a pressure responsive device while draining fluid from the opposite end, it being understood that the resulting movement of the pressure operated device tends to compensate for means are provided in the system for producing changes in the governing effect of the flyweights, so that a further control of flyweight position can be superimposed on the rather broad control thereof afforded by the counteraction between the spring 60 and the centrifugal force exerted by the flyweights. To this end, magnetic forces are used which may be arranged to operate either with or against the effect of centrifugal force, and the magnetic forces may be less or greater than the centrifugal forces exerted upon the flyweights, as desired. Because of the fact that magnetic means are used to eifect this additional control, it Will be clear that an immediate response of the flyweights thereto can be attained, and thus a control can be produced which is capable of functioning with rapidity.

According to the embodiment of the invention illustrated in Figs. 1 and 2, the flyweights 54 are magnetized so as to have a pole at their upper free end. Immediately above the free ends of the magnet, there is located an annular electro-magnet 70 energized by suitable electrical leads 71, with the magnet having a lower face 72 annular in form and positioned just above the orbit of rotation of the flyweights. The core of the electro-magnet 70 has, of course, a multitude of wire turns wound concentric with the axis of rotation of the flyweights, and by passing a direct electrical current through the magnet coil a magnetic field is produced. When a current is passed through the coil, the same will act in the nature of a magnet, having one pole at the outer diameter of the coil indicated by the reference numeral 73, and the opposite pole along the inner diameter of the coil indicated at 74. An external magnetic field will extend between the poles of the electro-magnet, and thus will extend across the orbit of rotation of the upper poles of the magnet.

It now will be obvious that the strength and direction of the direct current fed into the electro-magnet 70 Will produce varying control effects on the permanently magnetized flyweights, and will either accentuate the centrifugal force to Which such flyweights are subjected or counteract such centrifugal force, depending upon the direction in which the current passes through the electromagnet. The intensity of the'current will, of course, vary the intensity of the effect.

The result of'the foregoing is that the eifective'mass of the flyweights is varied, or more broadly, the massmoment of the flyweights can be attenuated or augmented by the electrical means provided.

If for any reason the use of permanent magnets as flyweights should not be desired, the modification of the invention shown in Fig. 3 may be utilized. As previously indicated, this figure shows a centrifugal governor generally similar to that of Fig. 1, including a flyweight chamber 100 in which flyweights 101 are rotated by means of an annular member 102 secured to a driving sleeve. The flyweights are pivotally mounted as indicated at 103, and are provided with inwardly extended legs 104 operated to lift the stem 105 of the pilot valve as the flyweights pivot outwardly. Such lifting movement of the stem 105 is opposed by a compression spring 106 seated at one end on a seat 107, in turn supported by a bearing'108, with the spring'being seated at its other end against an adjustment bolt 109. An electro-magnet 110, wound as previously indicated for the magnet 70, is furnished with electrical current by means of suitable leads 111. The housing portion 112 immediately surrounding the electro-magnet is provided with a depending sleeve portion 113 terminating in 4 an annular collar 114 surrounding the lower portion of the path of rotation of the flyweights. The flyweights 101 are constructed of highly permeable metal. When current is passed through the coil of the 'electro-magnet 110, the collar 114 becomes in efiect one pole of the magnet, the other pole being located along the inner diameter of the electro-magnet, indicated by the reference numeral 115. The magnetic field extending between the collar 114 and the inner diameter 115 passes through the flyweights 101, and by motor action, the flyweights thus have a torque exerted on them by the magnetic field, which'serves to urge the flyweights to an oriented position offering the minimum of reluctance to the passage of flux in the magnetic circuit. In this system, of course, the direction of'current flow through the coil has no effect on the flyweights, since they move only to reduce the flux density across their pole faces. While the force exerted by the electro-magnet on the flyweights is uni-directional, it is sensitive to magnitude of the electrical current in the coil and changes in the intensity of the current produce corresponding changes in the torque eflect upon the flyweights.

It will be perfectly clear that the leads 71 or 111 can be connected to suitable sources of electrical energy wherein the magnitude of the current supplied (and in the case of the device of Fig. 1, the direction thereof) will be a function of a control sensitive to output of the element being controlled. Thus a relatively simply constructed governor may, by utilizing the present invention, be modified into one susceptible to extremely fine and continuous control and susceptible to eifective compensation in areas of response time beyond the capability of the flyweight governor alone.

It will be obvious to those skilled in the art that the electrical control of the governors disclosed herein provides a system for controlling the flyweights which is extremely simple and can be made in a manner to be substantially trouble-free. The governor control is free from hysteresis at all points within its range of operation and is reversible and can operate plus and minus from a null point without discontinuity. The trimming force exerted on the flyweights by the magnetic forces involved can be applied and modulated with great speed compared to the speed with which the flyweight force can be changed by a change in speed of the controlled member. Thus the governor system provided by the present invention is particularly adapted for use in situations where rapid corrections of large or small magnitude are desired in the proper operation of the complete system.

I claim:

1. A governor device comprising a housing, a rotatably mounted flyweight carrier in the housing, a flyweight pivotally mounted on the carrier and having a portion extending from the pivotal mounting generally parallel to the axis of rotation of the carrier and terminating in a magnetized end, means for rotating the carrier to revolve said magnetized end in an orbit, means fixed in the housing against rotation with the carrier for creating a magnetic field having one pole adjacent said orbit, said one pole being in the form of an annulus concentric with and larger in diameter than said orbit, said magnetic field having its other pole'adjacent said orbit, said other pole being in the form of an annulus concentric with and larger in diameter than said orbit, and means for varying the intensity of said magnetic field.

2. A governor device comprising a rotatably mounted flyweight carrier, an elongated flyweight pivoted to the carrier adjacent one end thereof to position the flyweight with its major axis extending away from said juncture approximately parallel to the axis of rotation of the carrier, said flyweight being magnetized to have a mag netic pole at its free end, means for rotating the carrier to revolve said free end in an orbit, an annular electromagnet positioned adjacent and parallel to said orbit and spaced from the flyweight, said electro-magnet having a first annual pole smaller in diameter and adjacent said orbit and a second annular pole larger in diameter and adjacent said orbit, and means for transmitting an electric current to said electromagnet to create a magnetic field extending across said orbit and biasing said flyweight toward pivotal movement relative to the carrier.

3. A governor device comprising a rotatably mounted flyweight carrier, a generally L-shaped flyweight pivoted to the carrier at approximately the juncture of the legs thereof to position the flyweight with one of its legs extending away from said juncture approximately parallel to the axis of rotation of the carrier, means for rotating the carrier to revolve said one leg in an orbit, an annular electro-magnet positioned adjacent but spaced from said orbit and having a first annular pole smaller in diameter and adjacent said orbit and a second annular pole larger in diameter and adjacent said orbit, and means for transmitting an electric current to said electro-magnet to create a magnetic field extending across said orbit and biasing said flyweight toward pivotal movement relative to the carrier.

4. A governor device comprising a rotatably mounted flyweight carrier, a generally L-shaped flyweight pivoted to the carrier at approximately the juncture of the legs thereof to position the flyweight with one of its legs extending away from said juncture approximately parallel to the axis of rotation of the carrier, said one leg of the flyweight being of highly permeable metal, means for rotating the carrier to revolve said one leg in an orbit, electro-magnet positioned adjacent said orbit and having a first annular pole adjacent the free end of said one leg and having a second annular pole of diiferent diameter than the first pole and positioned adjacent the other end of said one leg, and means for transmitting an electric current to said electro-magnet to create a magnetic field extending between the annular poles and biasing said one leg toward a position of minimum reluctance in said field.

5. A governor device comprising: a rotatably mounted flyweight carrier, a flyweight movably mounted on the carrier, means for rotating the carrier to revolve the flyweight in an orbit, means for creating a magnetic field having one pole adjacent said orbit, said one pole being in the form of an annulus concentric with and smaller in diameter than said orbit, said field creating means having its other pole adjacent said orbit, said other pole being in the form of an annulus concentric with and larger than said orbit, both of said poles being fixed against rotation with the carrier, and means for varying the intensity of said magnetic field.

References Cited in the file of this patent UNITED STATES PATENTS 531,849 Melott Jan. 1, 1895 2,643,871 Warrick June 30, 1953 2,677,539 Winslow May 4, 1954 2,715,528 Schulte Aug. 16, 1955 FOREIGN PATENTS 55, 077 Austria Apr. 10, 1912 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 4 Patent No, 23390 877 June 16 1959 I Donald A, Straznickas It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4 line 61 for "larger", read smaller column 5, line 1, for "annual" read annular Signed and sealed this 4th day of April 1961,

(SEAL) Attest: ERNEST W. SWIDER WXXWNK ARTHUR w. CROCKER Attesting Oflicer A ti Commissioner of Patents

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