US3451405A - Centrifugal flyweight engine governor - Google Patents

Description

June 24, 1969 J. M. BAILEY ET-AL 3,451,405

CENTRIFUGAL FLYWEIGHT ENGINE GOVERNOR Filed June 19, 196 Sheet of 3 INVENTOR-S JOHN M. BAILEY STEPHEN F GLASSEY BY WALDEMAR A. STANIAK 7% 7, *w'fl ATTORNEYS June 24, 1969 BM EI'AL 3,451,405

CENTRIFUGAL FLYWEIGHT ENGINE GOVERNOR Filed June 19, 1967 Sheet f 01 3 INVENTORS JOHN M. BAILEY. STEPHEN E GLASSEY WALDEMAR A. STANIAK June 24, 1969 J. M. BAILEY ETAL 3,451,405

CENTRIFUGAL FLYWEIGHT ENGINE GOVERNOR Filed June 19, 1967 Sheet 3 of a INVENTORS JOHN M. BMLEY STEPHEN F GLASSEY WALDEMAR A. STANIAK BY 7 2w, 7% #4.,

. ATTORNEYS 4 United States Patent CENTRIFUGAL FLYWEIGHT ENGINE GOVERNOR John M. Bailey, Dunlap, Stephen F. Glassey, East Peoria,

and Waldemar A. Staniak, Peoria, Ill., assiguors to Caterpillar Tractor Co., Peoria, 111., a corporation of California Filed June 19, 1967, Ser. No. 647,098 Int. Cl. F01b 25/02; F01c 21/12; F01] 15/00 U.S. Cl. 137-18 Claims ABSTRACT OF THE DISCLOSURE Precision regulation of fuel injector pumps or the like is accomplished by a compact and simple flyweight mechanism carried on a rotating shaft which may be coupled directly to an engine drive train without speed increasing means. In a preferred form, the flyweight mechanism has a carrier coupled to the rotating shaft for retaining and driving contacted pairs of annular flyweights which may move radially, in response to increasing centrifugal force, to exert an axial force on a pair of convergent ramps. The flyweights may also shift in a direction parallel to the rotating shaft. Positioning, synchronizing and driving of the flyweights are all effected through the carrier.

Background of the invenzl'on This invention relates to engines and more particularly to centrifugal governors for regulating the speed thereof.

Speed governors for automotive engines and the like generally have some form of rotating flyweight which moves outward from the axis of rotation, in response to centrifugal force changes, together with means for translating this motion into linear movement for operating linkage controlling fuel injection pumps, a carburetor, or the like. Changing the setting of the fuel pump or the like in this manner may require a sizable force and thus the flyweights must be fairly massive or else must be made to turn at very high speeds. This consideration and the nature of the flyweight mechanism designs heretofore employed, have resulted in bulky and complex constructions. Where the necessary force is obtained by increasing the speed of the flyweights relative to the engine drive train, undesirably high stresses are created and wearing of certain component elements is accelerated. In addition to being bulky and subject to wearing, such governors are costly to produce and require considerable main tcnance.

Where a governor is used with a vehicle engine, it is frequently desirable to avoid impeding the operators sense of control over engine speed. This is commonly done by utilizing the maximum-minimum type of governor which is arranged to exert a speed controlling effect only at the terminal portions of the range of operating speeds. The structural complications for this purpose have also contributed to the bulk and cost.

The flyweights in many conventional governors are pivoted elements which swing outward from a rotating shaft, in response to speed increases, against the action of springs. Because these flyweights are pivoted, usually only about one-half of the mass thereof is available to provide the force for operating speed control linkage. This inefliciency again requires greater bulk or greater operating speed than would otherwise be necessary.

These problems have been resolved in part in another form of governor in which the flyweights are not pivoted to a rotating shaft, but are pairs of cylindrical or spherical elements situated between convergent ramp surfaces. Such elements are capable of moving more or less directly outward relative to the rotating shaft to wedge the ramps apart and thereby produce an axial movement of at least one of the ramps for controlling the fuel injectors or the like. However, as heretofore designed, these structures have still been undesirably bulky, complex, prone to rapid Wear, and subject to substantial friction at the flyweights. Among other complications, it has heretofore been the usual practice to drive the flyweights through the associated ramps and this results in a significant friction loss and in accelerated wearing.

Summary of the invention The present invention is a compact, simple and wear resistant governor of the class having pairs of rotatable flyweights bearing against convergent ramps and which turn with a drive shaft to produce a very strong force for controlling fuel pumps or the like. The paired flyweights are coupled to the drive shaft, and driven thereby through a carrier which provides for both radial and axial movement of the flyweights relative to the drive shaft and which further provides for synchronized rotation of the flyweights about axes parallel to the associated ramps. In a preferred form, the invention further provides very simple structure for effecting a maximum-minimum form of governor operation.

Accordingly, it is an object of this invention to provide a very compact, durable and highly eflicient governor for regulating the speed of engines.

The invention, together with further objects and advantages thereof, will be better understood by reference to the following description of preferred embodiments and by reference to the accompanying drawings.

Brief description of the drawings In the drawings:

FIGURE 1 is an axial section view of a first embodiment of the invention utilizing roller flyweights and in which the governor is shown coupled to the camshaft of a diesel automotive engine of the class having fuel injection pumps;

FIGURE 2 is a fragmentary section view taken along line II-II of FIGURE 1 showing rack. and pinion structure through which the governor controls the fuel injection pumps;

FIGURE 3 is a section view taken along line III--III of FIGURE 1 further illustrating the roller flyweights and associated elements,

FIGURE 4 is a perspective of linkage through which the governor of FIGURES 1-3 is coupled to the fuel injection pumps and through which the operator may control the governor;

FIGURE 5 is a view of the roller flyweights and certain associated elements of the structure of FIGURE 1 illustrating the position of the elements at a first stage in operation of the governor;

FIGURE 6 is a view corresponding to FIGURE 5 showing the elements thereof at a second stage of governor operation;

FIGURE 7 is an axial section view of a second embodiment of the invention utilizing pairs of spherical flyweights; and

FIGURE 8 is an exploded perspective view illustrating the carrier structure which retains and drives the spherical flyweights of FIGURE 7.

Description of the preferred embodiments Referring now to the drawing and more particularly to FIGURE 1 thereof, a portion of the fuel pump housing 11 of a diesel engine is shown including a portion of one of the fuel injector pumps 12. The injector pumps 12 are of conventional construction and are operated by a series of earns 13 on a cam shaft 14 which is coupled to the engine drive train and turns at a rate corresponding to the engine speed. Referring now to FIGURE 2 in conjunction with FIGURE 1, the quantity of fuel injected at each actuation of pump 12 can be adjusted in the conventional manner by longitudinal movement of a rack 15 having teeth 16 which engage a pinion gear 17 of the pump. The longitudinal movement of the rack 15, and thus the engine speed, is in turn controlled in part by the operator and in part by a governor 18 secured to the fuel pump housing 11 at the end of cam shaft 14.

Governor 18 has a cylindrical housing 19 which is coaxial with camshaft 14 and the end of the camshaft extends a short distance into the housing and is provided with a flange 21 which rides against a thrust bearing 22 disposed adjacent the outer surface of the fuel pump housing 11. A governor drive shaft 23 projects axially from the end of the camshaft 14 within housing 19 and carries a roller flyweight and ramp mechanism 24.

Mechanism 24 senses engine speed and, at the upper and lower limits of the speed range, operates the rack 15 to maintain the speed constant in the presence of variable loading. For this purpose, mechanism 24 has a pair of ramp members 26 and 27 which are transpierced by shaft 23 and which are slidable in an axial direction thereon. Ramp members 26 and 27 are situated Within a slot 28 defined by a pair of spaced apart camshaft projections 29 which extend parallel to the shaft 23 within governor housing 19 from the cameshaft flange 21. Ramp member 26 abuts the base surface of slot 28 while ramp member 27 contacts a thrust bearing 30 disposed coaxially on the shaft and which in turn abuts a sleeve 31 of a yoke 32 which is slidably disposed on the shaft in coaxial relationship thereto. Referring now to FIGURE 3 in conjunction with FIGURE 1, both ramp members 26 and 27 abut the inner faces of camshaft projections 29 so that both ramp memebrs are constrained to turn with the camshaft 14 and governor drive shaft 23. The rotary motion is not transmitted to yoke 32 owing to the presence of the thrust bearing 31.

Referring still to FIGURES 1 and 3 in conjunction, ramp member 27 is moved along shaft 23 in response to speed changes through the action of four pairs of rollers 33 which are disposed between the two ramps 26 and 27 and which tend to move radially outward from shaft 23 in response to the increasing centrifugal force which results from increases in the rotary speed of the shaft. To retain, synchronize, and drive the rollers 33, a carrier assembly 34 is disposed between ramps 26 and 27.

Carrier assembly 34 is comprised of a pair of carrier blocks 36 and 37 disposed within slot 28 on opposite sides of drive shaft 23. Both carrier blocks 36 and 37, as well as the drive shaft 23, are transpierced by a spindle rod 38 which is normal to the drive shaft. Carrier blocks 36 and 37 are thus constrained to rotate with drive shaft 23 while being capable of moving in a radial direction relative thereto along the spindle 38. Each carrier block 36 and 377 has a pair of slots 39 which are parallel to the drive shaft 23 with one slot facing ramp member 26 and the other slot facing ramp member 27. The rollers 33 are arranged in sets of two which are coaxial and spaced apart and connected by a shaft section 41 of reduced diameter which fits within of the slots 39 of the carrier blocks so that the associated two rollers 33 are slidable in the slot in an axial direction relative to drive shaft 23. Each roller 33 thus rides against the inside surface of one of the ramp members 26 or 27 and also contacts another roller 33 carried on the same carrier block 36 or 37, but in the other slot 39 thereof. Each roller 33 is thus paired with another by mutual contact to enhance synchronization of the flyweights.

To provide a maximum-minimum type of governor, as will hereinafter be discussed in more detail, the inside surfaces of the two ramp members 26 and 27 which are contacted by the rollers 33 have first surface sections 42 which are convergent at a first angle and have second surfaces of the two ramp members 26 and 27 which are 23 which are convergent at a still greater angle. Thus, as the rollers 33 and associated carrier blocks 36 and 37 move radially outwardly from shaft 23 through the action of centrifugal force, the ramp member 27 must be forced in an axial direction along the shaft and will move yoke 32 along the shaft in a similar manner through the thrust bearing 30.

Referring now again to FIGURE 1 in particular, to obtain a governor action the above described axial movement of yoke 32 must be resisted by yieldable means. For this purpose, a first compression spring 44 is disposed between the end of sleeve 31 and a flange 46 on a threaded rod 47. Rod 47 is coaxial with governor drive shaft 23 and is threadably engaged in an annular end cap 48 which is in turn threadably engaged in an opening 49 in the end of the governor housing 19. The degree of compression of first spring 44, which determines the low idle speed of the associated engine, may be adjusted by rotating the threaded rod 47 and a lock nut 51, hearing against end cap 48, is engaged thereon to hold the selected adjustment.

First spring 44 thus tends to resist movement of ramp member 27 and therefore tends to resist radial movement of the rollers 33 so that for a given rotary speed of the system, an equilibrium condition exists at which the rollers 33 are moved radially outward some specific amount and yoke 32 has an axial position along shaft 23 which is indicative of this engine speed.

If the governor 18 is designed to control engine speed throughout the full range of speeds, a single spring 44 may be utilized to resist the movement of the yoke 32. However, in this particular example of the invention, the maximum-minimum type of operation is desired and accordingly, a second and stronger compression spring 52 is arranged to supplement the action of the first spring 44 after the yoke 32 has traveled a distance corresponding to radial movement of rollers 33 to the junction between ramp surfaces 42 and 43. At this position of the rollers 33, a pair of arms 53 which extend outwardly from 0pposite portions of the yoke sleeve 31 contact an annular collar 54 which is coaxial with the yoke sleeve and slidable relative thereto. The second spring 52 extends between collar 54 and end cap 48 to resist further axial travel of the yoke 32 with a substantially greater force than that provided by spring 44 alone. Collar 54 has a flange 56 which abuts against stops 57 attached to the governor housing 19 to limit travel of the collar towards camshaft 14 to a position providing for the above operation of the spring 52.

Referring now to FIGURE 4 in conjunction with FIG- URE l, the motions of yoke 32 are transmitted to the rack 15 through a linkage 58 which also provides for speed selection by the operator except at the limits of the operating range. The arms 53 of yoke 32 connect through pivots 59 to parallel members 61 of a transverse directed lever assembly 62. Axial movement of the yoke 32 along shaft 23 is transmitted to the rack 15 by a link 63 extending between a pivot 64 at one end of the rack and a pivot 66 at one end of lever assembly 62. A speed control link 67, which may be selectively moved by the operator in the conventional manner to control engine speed, is coupled to a pin 69 journalled in a fixed portion 71 of the governor housing through an arm 72 which extends radially from the pin. Longitudinal movement of the operators control link 67 thus turns the pin 69. An additional arm 73 projects radially from pin 69 and has a slot 74 at the end which engages a pivot 68 at the end of lever assembly 62 opposite from pivot 66 thereof.

In operation, with reference to FIGURES l-4 in conjunction, rotation of the camshaft 14 produces a corresponding rotation of the elements of the flyweight mechanism 24. Owing to centrifugal force, the rollers 33 tend to move outward from shaft 23 with a force which is a function of the rotary speed of the system. In moving outward, the rollers 33 force the ramp 27 in an axial direction, and such movement is in turn transmitted to yoke 32 until the force produced by the rollers is balanced by the counter-acting force of spring 44 thereby establishing the low idle speed of the engine. As the yoke 32 moves to this balanced position, lever assembly 62 is pivoted about post '68 thereby moving rack 15 longitudinally to cause the required amount of fuel to be injected into the engine for the low idle setting. The low idle speed may be adjusted by rotating threaded rod 47 and lock nut 51. Moving the threaded rod 47 toward drive shaft 23 increases the force of spring 44 and thereby raises the idle speed; and retraction of the rod 47 decreases the idle speed.

The balanced position of yoke 32 is maintained until such time as the operators speed control linkage 67 is actuated. When link 67 is advanced by the operator to increase engine speed, lever assembly 62 is pivoted about pivots 59 and thus rack 15 is moved to increase the amount of fuel injected into the engine. As the engine speed increases, the resultant greater centrifugal force moves rollers 33 outward to the position illustrated in FIGURE 5. At this position, the rollers 33 contact the ramps 26 and 27 at the junctions between inclined surfaces 42 and 43, and the arms 53 of yoke 32 are abutted against collar 54. At this point, further axial movement of the yoke 32 is resisted by the stronger force of the second spring 52 so that still further engine speed increases, brought about by actuation of the operators control link 67, are transmitted to the rack 15 by lever assembly 62 without significantly affecting the position of the yoke 32 or rollers 33. Within the desired operating range of speeds, the engine speed is fully determined by the operators manipulation of control link 37 and does not involve control by the governor.

However, if for any reason the engine speed should exceed a predetermined upper limit, the still greater centrifugal force causes the rollers 33 to move outwardly along the sections 43 of ramps 26 and 27 again moving the yoke axially and this time against the action of both springs 44 and 52. This action pivots lever assembly 62 about post 68 and thereby pulls on rack 15 to decrease the amount of fuel being injected into the engine, thereby tending to restore the engine to the maximum desired speed. This maximum speed may be adjusted by turning the end cap 48 to vary the tension of the second spring 52. As illustrated in FIGURE 6, the elements are preferably proportioned so that the extreme limit of travel of yoke 32 is determined by seating of the arm 53 against stop 57, at which position rack 15 is moved to the point where the injection of fuel into the engine is completely cut 011?.

By comparing FIGURES 5 and 6, it may be seen that the rollers 33 must move in a direction parallel to the drive shaft 23 during operation of the governor. This is provided for by the slots 39 in carrier blocks 36 and 37. The carrier blocks 36 and 37 thus provide for both radial and axial freedom of movement of the rollers 33 relative to the shaft 23 while retaining and driving the rollers through a pivot-free coupling to the shaft. This construction results in a substantially enhanced conversion of the centrifugal force acting on the rollers 33 into a linear movement of the yoke 32 for regulating engine speed as described above.

Principles of the invention may be adapted for other forms of pivot-free flyweight mechanism. Referring now to FIGURES 7 and 8, a governor is shown in which the flyweight mechanism 24' utilizes pairs of ball elements 76 in place of rollers, with the ball elements being again driven, positioned and synchronized by means associated with the governor drive shaft 23'.

The structure of the governor 10 aside from the moditfied flyweight mechanism 24' may be essentially similar to that previously described and thus includes a housing 19' secured to an engine fuel pump housing 11 adjacent the end of camshaft 14. The governor 10 further includes a drive shaft 23' extending axially from camshaft 14 and a yoke 32 slidably disposed thereon and 6 i coupled to linkage 58' for actuating a fuel injection control rack 15. Movement of the yoke 32 is again resisted by a first spring 44' which is supplemented, after an initial period of movement of the yoke, by a second and stronger spring 52. An adjustable threaded rod 47' and an adjustable end cap 48" provide for adjusting the tension of springs 44' and 52', respectively, and thus for adjusting the low idle and maximum engine speed, respectively. The structure of the above described elements of the embodiments of FIGURES 7 and 8 may be essentially similar to the corresponding elements as hereinbefore described with reference to FIGURES 1 6.

Considering now the modified flyweight mechanism 24', a pair of dished circular ramp members 77 and 78 are disposed on drive shaft 23 and are slidable therealong. Ramp member 77tbears against the end of yoke 32' through a thrust bearing 30', while ramp member 78 abuts the end of the camshaft 14'. Referring now to FIGURE 8 in combination with FIGURE 7, a circular carrier plate 79 is disposed coaxially on drive shaft 23 between ramp members 77 and 78 and is coupled to the shaft 23 through a spline connection 81 or the like so that the plate is constrained to rotate with the shaft while being slidable therealong in an axial direction. As best shown in FIGURE 8 in particular, carrier plate 79 has four radially directed slots 82 at ninety degree angles therearound, each of which receives one of four tubular ball carriers 83. The carriers 83 are transverse to the plane of plate 79 and each carrier has a groove 84 along each of two opposite sides which receive the edges of plate 79 adjacent slots 82 so that the tubular carriers 83 are slidable in a radial direction along the slots while being held in perpendicular relationship to the carrier plate 79.

Referring now again to FIGURE 7 in particular, one of the ball elements 76 is disposed in each end of each of the tubular carriers 83 with each such ball elements riding against one of the ramp members 77 and 78. To retain the ball element 76 within the carriers 83, each end thereof is crimped inwardly about the adjacent ball and the two ball elements in each such carrier are in contact with each other.

The two ramp members 77 and 78 have surfaces facing the ball element 76 which are convergent in two stages 42 and 43' to provide the maximum-minimum type of governing action hereinbefore described with reference to the embodiment of FIGURES 1-6.

In operation, rotation of the drive shaft 23' turns the ball elements 76 owing to the coupling therebetween provided by the carrier plate 79 and tubular carriers 83. As the ball elements 76 move radially outwardly from shaft 23, through sliding of the carriers 83 along slots 82 as a result of increasing centrifugal force, axial pressure is exerted against yoke 32' by ramp 77 to regulate engine speed in the manner hereinbefore described.

What is claimed is:

1. In an engine governor having a rotary drive shaft and an element which is moveable to control the speed of said engine, the combination comprising:

a pair of ramp members disposed at said shaft and having convergent facing surfaces, a first of said ramp members being moveable in an axial direction relative to said shaft to shift said element for controlling the speed of said engine;

a plurality of flyweights disposed between said ramp members, said flyweights being arranged in pairs with each one of each of said pairs contacting a separate one of said ramp members at said convergent surface thereof, the fiyweights forming each pair thereof being rotatable about spaced apart parallel axes which are normal to radii of said drive shaft whereby said flyweights may roll against said convergent surfaces while moving outward from said drive shaft in response to centrifugal force; and

a carrier disposed between said ramp members and coupling each of said pairs of flyweights to said drive 7 shaft for rotation therewith and providing for both radial and axial movement of said pairs of fiyweights relative to said drive shaft.

2. The combination defined in claim 1 wherein component ones of each of said pairs of flyweights are in contact and jointly span the entire spacing between said convergent surfaces of said pair of ramp members.

3. The combination defined in claim 1 further comprising:

a first spring resisting a first portion of the movement of said first ramp member, and a second spring resisting a subsequent portion of the movement of said ramp member whereby said governor functions as a maximum and minimum speed regulator.

4. The combination defined in claim 3 wherein said convergent facing surfaces of said ramp members have radially innermost sections which are convergent at a first angle and have radially outermost sections which are convergent at a greater angle, the juncture between said sections of said convergent surfaces being at the radial position of said fiyweights corresponding to the axial position of said first ramp member at which said second spring is caused to resist further movement thereof.

5. The combination defined in claim 1 wherein said drive shaft is an axial extension of a camshaft of said engine and wherein said element which is movable to control the speed of said engine is an annular yoke slidably disposed on said drive shaft and moveable therealong in response to movement of said first ramp member.

6. The combination defined in claim 1 wherein said engine has means for varying the rate of fuel flow thereto and an operator actuated link for selectively varying speed, further comprising:

a lever having a central portion pivoted to said element which is moveable to control engine speed;

a first pivot coupling said operator actuated link to a first end of said lever; and

a second pivot coupling the second end of said lever to said means for varying fuel flow.

7. The combination defined in claim 1 wherein said flyweights are rollers and wherein said carrier is comprised of a spindle normal to said rotary drive shaft and a pair of carrier blocks each disposed on an opposite side of said rotary drive shaft and being slidable along said spindle in a radial direction relative to said drive shaft.

8. The combination defined in claim 7 wherein each of said carrier blocks has a slot extending parallel to said rotary drive shaft and wherein two of said fiyweights, each from separate ones of said pairs thereof, are coaxial and connected by a shaft extending therebetween which is received in said slot of said carrier block.

9. The combination defined in claim 1 wherein said flyweights are ball elements and wherein said carrier has a plurality of angular spaced passages extending parallel to said rotary drive shaft each having one of said pairs of fiyweights carried therein.

10. The combination defined in claim 9 wherein said carrier is comprised of a plate disposed coaxially on said rotary drive shaft between said ramp members and being moveable in an axial direction relative to said drive shaft and having a plurality of radially directed slots, and wherein said passages in which said pairs of ball elements are received are defined by tubular members transpiercing said slots and being moveable therealong in a radial direction relative to said rotary drive shaft.

References Cited UNITED STATES PATENTS 1,777,354 10/1930 Dina 13753 X 2,009,995 8/1935 Engel 13733 2,157,542 5/1939 Kieser 137-53 2,407,042 9/1946 Tippen 137 33 2,775,665 12/1956 I-Iarstick 73-551 X 2,926,901 3/1960 Jennings 7355l 2,962,037 11/1960 Simon 13753 2,968,951 1/1961 Gauthier 73551 X CLARENCE R. GORDON, Primary Examiner.

US. Cl. X.R.

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