US2369426A - Automatic compensating centrifugal governor - Google Patents

Description

Feb. 13, 1945. w. E. BENJAMIN AUTOMATIC COMPENSATING CENTRIFUGAL GOVERNOR Filed Jan. 30, 1943 2 Sheets-Sheet l Feb. 13, 1945.

w. E. BENJAMIN 2,369,426

AUTOMATIC GOMPENSATING CENTRIFUGAL GOVERNOR 2 Sheets-Sheet 2 Filed Jan. 30, 1943 INVENTOR.

Patented Feb. 13, 1945 UNI-TED STATES PATENT OFFIC AUTOMATIC COMPENSATING CENTRIFUGAL V GOVEBNDR Walter E. Benlamin, Anderson, Ind., assigner to Pierce Governor Company, Anderson, Ind.

Application January 30, 1943, Serial No. 474,095

14 Claims. (Cl. 12S-108) butterfly type and is mounted in a,throttle bodyinserted between the carburetor and intake manifold. The balanced valve eliminates to a great extent the velocity effect of the fuel `'supply thereon over the unbalanced valve, hence is preferred.

In governing lof the aforesaid character the control structure-.is directly responsive to engine speed, and in the typejllustrated. static and velocity pressures on governing valves vary, so that the torque exerted thereon by fuel mixture flow through the engine intake varies for different speeds and loads, etc. f"

The chief object of this invention is to offset this uneven torque pressure on the governing throttle valve, so that the latter .m truly directly and proportionally responsive to the centrifugal `control imposed on said valve.

The result is that extremely close governor regulation between no load and full load is possible, because the torque reactions on said valve between these loads is properly compensated for. l

The chief feature of this invention resides on the inclusion of governor valve torque pressure compensator in the form of a cam and follower structure that is arranged to impose a force on said valve at any position thereof substantially equal and opposite to the fuel mixture flow torque imposed thereon, with the result that there is in effect a negligible pressure result, or a pressure that is substantially constant for the full range of throttle valve travel.

'I'he present invention is, as evidenced by the charts, a substantially perfect exempliflcation of the basic invention disclosed in the copending application Serial No. 452,883 filed July 30th, 1942 although same is confined to a velocity governor only and incorporates therein `a compensating factor.

The present invention in like manner produces results that are phenomenal in that almost vertical line effect results at any governed speed for all loads. No governing structure known to date is comparable thereto. Applied to military equipment, as it now is, this invention holds the engine to the governed speed, so that approximately 25 B. H. P. additional is now available for hill climbing purposes and about four miles per hour more speed is available over the entire range of from no load to full load, for governed speed at full load.

Other objects and features of the invention will be set forth more fully hereinafter.

The full nature of the invention will be understood from the accompanying drawings and the following specications and claims:

In the drawings Fig. 1 is a diagrammatic central sectional view of a conventional centrifugally operable device, a side elevation of a governor throttle body, the power connection therebetween and e, side elevation of the valve torque compensating structure, parts being shown in the wide open throttle position, dotted lines indicating the governor valve closed throttle position.'

Fig. 2 is an end elevational view of the throttle body with governor connection and compensating structure attached.

Fig. 3 is a diagram of two curves from wide lopen throttle to closed throttle over a full range horsepower load against speed, and the third showing beam load of the brake against speed, the former all being the variable and the latter being substantially 2400 R. P..M. These curves are substantially constant vertical lines indicating constant regulation at any load and for different manifold pressure evidencing substantially exact and complete compensation from no load to full load at a given speed.

Fig. 5 is a diagrammatic side elevation of an engine including air cleaner, carburetor, manual 'r throttle, manifolds, throttle body, governor (engine driven) and connection therefrom to throttle valve shaft in the throttle body X indicating the valve and Y the manual control.

The corresponding curves for the device set forth in the copending application show a slight inclination crossing the selected speed near the higher vacuums or positive pressures and high load markedly broke to the left'in this range.

Valve torque compensation being substantially perfect in the present invention, there is none to transmit to the governor, so that surging back and forth to correct over a limited range (hunting) substantially is eliminated to a degree heretofore unknown in a centrifugal governor mechanically connected to a throttle valve.

In Fig. l of the drawings, I indicates a housing of a centrifugally operable structure secured to a portion of the engine by bolts II and having a lateral opening by which a gear I2, keyed at I3 to the centrifugal shaft I4, can engage and mesh-with an engine, or engine driven gear, so that shaft I4 is rotatable at, or proportional to engine speed.

Shaft I4 is rotatably supported in anti-friction bearings I5 and I6, the latter being mounted in the housing extension Illa. Longitudinally slidable on, but rotatable with shaft I4, is sleeve I1. Rigid with shaft I4 is base I8, to which is pivoted at 9 the centrifugal force responsive weights 20, having tail or finger portions 2I positioned adjacent one end of sleeve I1.

At a predetermined engine speed, determinable by the load spring adjustment and spring selected, these weights, due to centrifugal force, tend to move outwardly and upon doing so, their tail portions slide sleeve I1 upon shaft I4. Herein sleeve I1 is illustrated as mounting an antifriction bearing member 2-2 at the end opposite the tail engageable portion.

A yoke lever pivoted at 23 has spaced portions 24 engageable by bearing 22. Thus the lever 25 is tiltable byv weight movement responsive to centrifugal force. A load spring 26 bears at 21 upon lever 25, being retained thereon by stem guide 26. Housing .I0 is threadedly apertured at 29 and an externally threaded socket type cap, having socket. 30 and knurled head 32, seats the other end of said spring. and may be manually rotated, respectively. for adjusting the initial force of such load spring. Look nut 3l holds the adjustment.

This spring normally opposes centrifugal movement of the weights at all times. When the centrifugal force is sufllciently great, the weights move, as described, and hence tilt lever 25. This is the control lever and is usually connected to the governing member, such as a butterfly valve in a passage through a throttle body in the engine intake system.

All of the aforesaid describes a conventional centrifugal governor, and in the present invention the same is not disturbed, but the effect of other forces, as initially described herein, are of such character that this theoretical operation is modified to that extent. The present invention automatically compensates for such forces, so

. that the actual governing operation is substantially the theoretical operation.

Herein, see Fig. 1, lever |25 outside of the governor housing and rigid with shaft 23, supports a pin type end 33 of a rod 34, which may be of adjustable length type. At its opposite end, this rod is pivotally connected at 35 to a lever arm 36, rigid with an exposed end of throttle shaft 31, pivoted in throttle body 38 interposed in the engine intake system downstream of the carburetor and usually between the carburetor and engine manifold connecting flanges, see Fig. l.

Herein shaft 31 projects through the body and on 'its other exposed end mounts another arm 4I pinned thereto as at 42. This shaft may be mounted in anti-friction bearings (not shown). The free end of arm 4I mounts on pivot 44, the

roller or follower 46. An anti-friction race 43 may be interposed between pivot 44 and roller 45 wherever desired or required. l

The aforesaid several anti-friction bearings broadly are conventional to standard governor practice, wherefor same are not illustrated in detail.

Pivotally supported at 46 on the throttle body,

and adjacent arm 4I, is member 41. 'I'he roller and member 41 lie in a common plane. Member 41 is of bell crank type with arm 48 having flat face 49 perpendicular to line A-B and lying in the plane including the axis of shaft or pivot 46. Roller 45 contacts face 49 at all times. The other arm 50 of -bell crank 41 has eye 62 in its outer end and the center thereof lies in'plane A-B. Accordingly, plane of face 49 is at right angles to center of the eye 52.

A light spring 5| has one end secured to eye 52 and its. opposite end is secured to eye 53 in the anchor member 64 threaded into boss '55 on plate 56 rigid with the throttle body. The spring ends are aligned at wide open throttle, for the longitudinal axis of anchor member 54 lies in plane A-B. The tension of this spring, which is light, but sufficient for compensating purposes, can be adjusted by moving member 54 toward and away from the axis of pivot 46.

Obviously the spring 5I always constrains the face 49 into roller contact, so that the force of this spring tends to hold the valve open and in an amount equal to the torque on-the valve imposed by fuel ow in the intake when the governor valve is moved toward closed' position. This torque is in the valve closing direction, The spring force is opposed thereto.

Now, as the valve is governor closed the arm 48 must move clockwise. In So doing arm. 50 moves therewith. Now, since spring 5I is under initial tension, it, when the arm is so moved elongates or stretches, hence its force increases as the arm is moved.

Y Here follows the gist of this invention and -the key to its success. Observe, see Fig. l, that at open valve position the arm 4I lies parallel to arm 48. f When spring 5I is adjusted, this is the idle or non-governing position. With a balanced valve the fuel flow torque thereon is zero, see

curve Fig. 3.

Now, with a 60 throttle valve movement to closed throttle, the arm 4I is then transverse to arm 48. Also, the torque curve again is zero, because now no fuel flows in the intake. However, at this position spring 5I is more elongated than ever.

With the valve half open, the torque is greatest. In this position arms 4I and 48 are midway vbetween the aforesaid limiting positions and spring 5I is elongated, but partially from idle zero position to its finally extended position.

The actual effective spring balancing force, accordingly, from 30 to 60 of throttle valve is proportionately decreased despite its (the spring) extension or increase. 'Ihis is because so far as arm 4I is concerned, the pressure of arm 48 thereon, effective to throw the valve open, if'the governor force be removed, (or flip open) is only the decreasing regular function thereof,

- from 30 to 60, respectively.

This explains why there is not an absolutely vertical line in Fig. 4, and this angular function cancellation is exactly equal in amount at all valve positions to produce an actual sine curve balancing force, compare the two curves in Fig. 3.

ascuas However, the curves are so close as to be substantially identical with the results described.

The mechanical advantages of the present invention over that disclosed in the pending application are that first in common therewith a longitudinally extensible spring is utilized, but herein the adjustment possible can be of micrometer variation, which is impossible in the assemblage of said application. This means that the slight variations which always are present in a lotof commercial springs of a specified diameter, length and force, can` be readily adjusted for. in effect eliminated, so that accurate spring selection is not required. A more important advantage, however, exists in that a iiat face is always a flat face and, hence, no variation occurs in manufacture. Such is not the case with the sinusoidal face of the application cam. The least variation in the face at any point will introduce an error in the correction desired. Also, there is a mechanical function error inherently present in said pending application structure for which no compensating internal correction is provided and this accounts for the departure of its curves from the curves herein, as previously mentioned.

All the aforesaid, however, is solely intended to show that present invention is substantially perfect, whereas the invention disclosed in the pending application. while phenomenally better than any heretofore known, actually did not reach perfection, although it was very close thereto.

While the invention has been illustrated and described in great detail in ,the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in char-` The modification described herein, as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

l. In an engine governing mechanism including a substantially balanced butterfly valve for engine intake throttle control and a centrifugally operable structure responsive to engine speed and directly connected to said valve for operation thereof, the combination of an arm rigid with said valve, a bell crank lever adjacent thereto, having an arm with an elongated ilat face for operatively engaging the end of the valve, at wide open throttle position the longitudinal axis of the valve arm lying parallel to the plane of the face and at closed throttle being substantially transverse thereto, said bell crank having another arm, the free end thereof forming a spring anchorage, the longitudinal line including such anchorage and the lever pivot axis being substantially perpendicular to the plane of the face, another spring anchorage in alignment with the longitudinal line only whenl the aforesaid parallelism exists, and a coiled light tension spring secured at opposite ends to said anchorages for substantially perfect compensation for the intake fuel flow torque on said valve for substantially all governed positions of said valve and constraining the bell crank to valve arm contact.

2. A governing mechanism as defined by claim 1 wherein the plane of the ilat face passes through the pivot axis of the bell crank lever.

3. A governing mechanism as defined by claim 1 wherein the spring ends are of loop character 1 wherein the spring ends are of loop character and lie in a plane common to the longitudinal line and substantially transverse to the face plane. the latter plane passing through the pivot axis of the bell crank lever.

5. A governing mechanism as defined by claim 1 wherein the second mentioned spring anchorage is an eyeletted elongated threaded member for wide open throttle initial spring force adjustment and commercial spring variation compensation.

6. A governing mechanism as defined by claim 1 wherein thevalve arm terminates in a flat face roller follower, the axis of whichroller lies perpendicular to and intersects the longitudinal axis of said valve arm.

7. A governing mechanism as deilned by claim 1 wherein the valve arm terminates in a ilat face roller follower, the axis of which roller lies perpendicular to and intersects the longitudinal axis of said arm, and there is included an anti-friction support between the roller follower and the valve arm.

8. A governing mechanism as dened by claim 1 wherein the valve arm terminates in a ilat face roller follower, the axis of which roller lies perpendicular to and intersects the longitudinal axis of said valve arm, and the second mentioned spring anchorage is an eyeletted elongated threaded member for wide open throttle initial spring force adjustment and commercial spring variation compensation.

9. A governing mechanism as deilnedby claim 1 wherein the valve arm terminates in a at face roller follower, the axis of which roller lies perpendicular to and intersects the longitudinal axis of said valve arm. and there is included an antifriction support between the roller follower and said valve arm, and the second mentioned spring anchorage is an eyeletted elongated threaded member for wide open throttle initial spring force adjustment and commercial spring variation compensation,

10. A governing mechanism as defined by claim 1 wherein the valve arm terminates in a iiat face roller follower, the axis of which roller lies perpendicular to and intersects the longitudinal axis of said valve arm, and the plane of the dat face passes through the pivot axis of the bell crank lever. 1

11. A governing mechanism as defined by claim 1 wherein the valve arm terminates in a at face roller follower, the axis of which roller lies perpendicular to and intersects the longitudinal axis of said valve arm, and there is included an antifriction support between the roller follower and the valve arm, and the .plane of the flat face passes through the pivot axis oi' the bell crank ever.

12. A governing mechanism as defined by claim l wherein the spring ends are of loop character and lle in a common plane and common to the longitudinal line and substantially transverse to Y longitudinal line and substantially transverse to the face plane, the latter passing through the pivot axis of the bell crank lever, the second mentioned spring anchorage is an eyeletted elongated threaded member for wide open throttle initial spring force adjustment and commercial spring variation compensation.

14. In an engine governing mechanism including a substantially balanced butterfly valve for engine intake throttle control and a centrifugally operable structure responsive to engine speed and directly connected to said valve for operation thereof, the combination of an arm rigid with said valve and a single elongated tension spring anchored at one end and operatively connected at its other end to said arxnv remote from the valve axis thereof, said arm at open valve position having a general direction angular to the plane of the valve, the general direction of the spring at open valve position being angular to said arm and the plane of the valve, the spring-arm relationship at open valve position being such that substantially no springforce is eiective upon the valve, and at closed valve position substantially no springv force is effective upon the valve, `the force, direction and eil'ect of said spring varying therebetween for loading the valve tocompensate for velocity eil'ect thereon .betwen said extreme positions thereof, the spring in intermediate valve positions, pulling towards open valve position.

WALTER E. BENJAMIN.

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