US2685440A - Speed and acceleration responsive governor - Google Patents

Description

Aug. 3, 1954 F. G. FREEMAN SPEEDAND ACCELERATIONRESPONSIVE GOVERNOR' Filed Jan. 5, 1953 -I1?/v 1 G. TIDE em Patented Aug. 3, 1954 FFICE SPEED AND ACCELERATION RESPGNSIVE GOVERNOR Frank George Freeman, Solihull, England, as-

signor to Joseph Lucas (Industries) Limited, Birmingham, England Application January 5, 1953, Serial No. 329,704

1 Claim. 1

This invention relates to speed governors for controlling the supply of liquid fuel to jet engines, gas turbines or other engines.

A governor in accordance with the invention comprises the combination of a hollow rotor, a pair of ra ially movable masses contained in the rotor, a spring loaded and axially movable abutment plate in the rotor, and wedging means in association with the centrifugal masses for imparting a fuel-controlling axial movement to the abutment plate.

In the accompanying drawing:

Figure l is a sectional side elevation illustrating one embodiment of the invention for actuating the control valve of a liquid-operated servo mechanism.

Figure 2 is a face view of the centrifugal masses, and Figure 3 is a fragmentary sectional plan to a larger scale than Figure 2 showing one .pair of associated grooves in one of the centrifugal masses and the abutment plate.

Figure 4 is a similar view to Figure 1, illustrating a modified embodiment of the invention for actuating an electric switch.

Referring to Figures 1-3, there is contained Within a stationary hollow body part a a hollow cylindrical rotor b, the latter being provided with a driving spindle 0 through which motion is imparted to the rotor from any convenient rotary part of the engine. On one of the inner end surfaces of the rotor is secured an insert d, and adjacent to the insert are arranged a pair of radially movable centrifugal masses 6 of semi-circular form, the driving connection between the rotor and the said masses bein effected by balls 1 engaging grooves in the adjacent faces of the parts cl, e. Alongside the centrifugal masses there is also contained in the rotor an axially movable abutment plate 9 which is loaded by a spring h.

The driving connection between the centrifugal masses and the abutment plate is effected by balls 1 engaging grooves 9, k the bases of these grooves being oppositely inclined as shown in Figure l. The corresponding groove occupied by the balls 1 are preferably similar to those occupied by the balls 2'.

The mode of action is such that when the speed of the rotor obtains a predetermined rate, the centrifugal masses move radially outwards, and through the wedging action of the balls 2' on the surface of the associated grooves 7', it, an axial movement is imparted to the plate 9. When similar grooves are provided between the parts (1, e axial movement is also imparted to the centrifugal masses, thus increasing the amount of axial movement given to the plate 9 Alternatively, the axial movement given to the abutment plate may depend only on the interaction of the balls and their associated grooves, but wedging means are preferably provided at each side of the centrifugal masses.

In the example shown in Figure l, the axial movement of the plate g is transmitted through a stem m, to a lever it contained in a bi-compartmental chamber 0 formed or mounted on the body part a. This lever extends through and is pivoted in a partition between the two compartments, and the end remote from the stem m is loaded by a spring 10. Also on this end is carried a closure member (1 which co-operates with a seating r at one end of a vent passage s extending from one end of the cylinder '12 of a liquid-operated servo mechanism.

The servo mechanism is of known form and comprises a piston u slidable in the cylinder and loaded by a spring 1). Both ends of the cylinder are in communication with each other through a restricted orifice w in a passage x. Motive liquid from any convenient source is admitted to the cylinderv through a passage 2. When the vent passage 5 is closed, the spring 2) moves the piston to the right, and the rod 3 extending from the piston actuates any appropriate fuel con trolling means. Thus the movement of the rod 3 may be utilised to reduce the output of a fuelsupply pump, or to control a throttle or by-pass in the fuel supply pipe for reducing the rate of flow of liquid fuel to the engine. When the closure member q is moved off its seating by the action of the centrifugal masses e, the preponderating pressure of the motive liquid acting on the right hand side of the piston moves the latter against the action of the spring 11 for increasing the rate of supply of fuel. Liquid escaping through the vent passage s is returned to a sump, through a drainage passage i in the chamber 0.

In the modified embodiment of the invention shown in Figure 4, the lever n is adapted to actuate a switch 5 in the circuit of a solenoid winding 6, the closure member q which controls the servo mechanism being mounted on the movable part I of the solenoid, which part is loaded by a spring 8. In this example, the chamber 0 has a single compartment, and the drainage passage 4 is provided in the hollow body part 9 containing the solenoid.

To enable an antecedent or anticipatory effect to be obtained by the governor, the grooves (i, k in the parts 6, 9 and/or the grooves in the parts d, e are made of pyramidal form, their side faces being mutually inclined as shown in Figure 3. During acceleration of the speed of the rotor, and particularly when the speed i approaching the critical speed at which the centrifugal masses can move radially outwards, the inertia of the centrifugal masses tends to cause them to lag relatively to the rotor, and the consequent interaction of the balls and the inclined side faces of the grooves results in an axial movement of the plate 9 causing the valve q to be opened before the critical speed is attained. If the acceleration ceases before attainment of the critical speed, the balls will resume their initial positions When the centrifugal masses rotate at the same speed as the rotor and the valve q will be re-closed. But if the acceleration continues until the critical speed is reached the centrifugal masses will move outwardly, and cause the valve q to he held in the open position. This antecedent effect is useful inasmuch as it prevents, or reduces the risk of, the speed of the rotor temporarily exceeding the critical speed.

By this invention a speed governor of the kind adapted to effect a controlling action at a predetermined speed is provided in a very simple form.

Having thus described my invention What I claim as new and desire to secure by Letters Patent is:

A speed governor for controlling the supply of liquid fuel to an engine, comprising in combination a hollow rotor provided with a driving member, a pair of radially movable centrifugal masses in said rotor, a supporting member at one side of said masses, 2. spring-loaded and axially movable abutment plate situated in said rotor at the other side of said masses, and Wedging means in the form of balls arranged to co-operate with said masses for imparting axial movement to said abutment plate in response to radial movements of said masses, the latter and at least one of the adjacent faces of said supporting member and abutment plate being formed with oppositely inclined grooves in which said balls are located, and said grooves being provided with inclined side surfaces for interacting with said balls to effect an antecedent movement of said abutment plate during acceleration of said rotor.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 736,277 Lombard Aug. 11, 1903 2,288,382 Adler June 30, 1942 2,613,784 Chilton Oct. 14, 1952 FOREIGN PATENTS Number Country Date 151,935 Germany June 2, 1904

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