US3468223A - Hydraulic governor for internal combustion engines - Google Patents

Description

Sept. 23, 1969 o, SENF 3,468,223

HYDRAULIC GOVERNOR FOR INTERNAL COMBUSTION ENGINES Filed Dec. 26, 1967 2 Sheets-Sheet 1 INVENTOR OAKLAN R. SENF BY /M W ATTORNEYS Sept. 23, 1969 o. R. SENF 3,468,223

HYDRAULIC GOVERNOR FoR INTERNAL COMBUSTION ENGINES Filed Dec. 26, 1967 2 Sheets-$heet 2 INVENTOR OAKLAN R. SENF BY M v ATTORNEYS United States Patent US. Cl. 91-458 7 Claims ABSTRACT OF THE DISCLOSURE A governor having a master piston and mountable on the cam shaft of an internal combustion engine is hydraulically connected to a slave unit having a slave piston connectable to a fuel control member and speedsensing means cause both pistons to move in response to variations in speed of the cam shaft. The speed-sensing means comprises a series of balls supported by a pair of races mounted on the cam shaft, one race being axially fixed and the second race being axially movable and adapted so that radial movement of the balls caused by a change in centrifugal forces acting on the balls causes an axial displacement of the movable race. The movable race forms the master piston in the master cylinder so that the radial motion of the balls is reflected through the master cylinder to the slave piston.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to centrifugally actuated hydraulic governors for internal combustion engines and more specifically to a governor actuated by the radial movement of a series of balls retained by a pair of races mounted on a rotating engine shaft, the races being adapted so that radial movement of the balls produces an axial displacement of one of the races which forms the pumping member of a fluid control cylinder.

Description of the prior art Centrifugal governors are widely employed as a means for controlling the speed of internal combustion engines. Such devices normally take the form of a weighted mass mounted upon a rotating engine member in such a manner that its radial position relative to the axis of rotation of the member varies with the rotational speed of the member. The radial motion of the weighted mass is transmitted through a suitable linkage to a control member such as a throttle valve or a carburetor control member. In this way the weighted mass upon sensing a change in engine speed produces a compensating adjustment in the fuel supply.

One problem associated with governors of the aforementioned type is that the linkage between the speed sensing weights and the control mechanism adds friction to the system and, in addition, loses its sensitivity as the various linkage elements progressively lose their tolerances under the influence of wear.

In order to obviate the problems of purely mechanical governor systems, some of the prior art discloses systems where the speed sensing weights are mechanically linked to some form of hydraulic device. Such systems require a number of different precision components such as pumping pistons, valves, needles, orifices, and the like. Such systems require a considerable amount of space, special mountings depending on the type of engine and still retain a substantial portion of mechanical linkage.

3,468,223 Patented Sept. 23, 1969 ice SUMMARY The preferred embodiment of the present invention is described as a governor comprising a speed-sensing means mounted on an engine cam shaft and operatively connected to the throttle member of the engine by a hydraulic system consisting of a master cylinder for reflecting changes in motion of the speed-sensing means and transmitting these changes through a closed hydraulic system to a slave piston connected to the throttle member.

The speed-sensing means comprises a pair of ball retaining races mounted on the cam shaft which cooperate to retain a series of spherical balls in position around the shaft. One race is fixed against axial movement. The second race is spring biased toward the fixed race and has a frusto-conical surface in abutment with the balls so that as the balls move radially inwardly or outwardly relative to the axis of rotation of the cam shaft and under the influence of a change in rotational velocity of the cam shaft, the second race is axially displaced to a position corresponding to the speed of the cam shaft. The movable race forms the hydraulic pumping piston in the master cylinder so that the volume of the master cylinder varies as the movable race is axially displaced. The slave cylinder is connected by a hydraulic tube to the master cylinder so that the slave piston moves with the master piston. The piston in the slave cylinder is coupled through a simple linkage to the throttle valve which constitutes the only mechanical linkage in the system.

A further improvement in the system constitutes the provision of a clearance between each piston and the sidewall of its associated cylinder. A rolling type diaphragm mounted between the piston and the cylinder provides a fluid seal that reduces friction and keeps losses due to hysteresis extremely low.

The preferred embodiment of the invention can be made into a compact unit that can be mounted on most internal combustion engines using very little space. It can be mounted on either side of the engine without the necessity of special linkages to provide a connection with the throttle or carburetor, so that there are no external, moving linkages, springs, rods and the like. The governor contains its own hydraulic fluid so that contaminates cannot get into the system. By arranging the movable race such that it forms the pumping member of the master cylinder as it reflects the centrifugal motion of the balls, the mechanical mechanism of conventional systems is eliminated. This reduction in mechanical components is reflected in a better speed-sensing capability and lower energy losses in the governor.

The aforementioned advantages of the invention will become more apparent to one skilled in the art to which the invention pertains upon reference to the following detailed description.

DESCRIPTION OF THE DRAWINGS the centrifugally-actuated ball-s shown in one position in solid lines and in another position in phantom; and

FIGURE 2 is an axial view of the master cylinder of FIGURE 1 connected to the slave cylinder which is in section.

DESCRIPTION OF THE PREFERRED EMBODIMENT Now referring to the drawings, the preferred governor comprises speed-sensing means generally indicated at 10 and a master hydraulic cylinder assembly 12 mounted on the end of an engine cam shaft 14. The master cylinder is fluidly connected through a conduit 16 (FIG. 2) to a slave unit 18 operatively connected to a movable control member as throttle member 20 of the engine. The speed-sensing means upon sensing a change in the rotation relation to the shaft by a Woodruff key 28. The justment in the throttle member to control the output of the engine.

The speed-sensing means 10 is mounted on the end of the cam shaft 14 adjacent a cam gear 22 (FIG. 1) which is mounted on the shaft 14 and is retained against axial displacement by a retainer 24 and a nut 26, and against rotation relation to the shaft by a Woodruff key 28. The camshaft 14 has an axial bore 32.

Still referring to FIGURE 1 the speed-sensing means 10 comprises an axially fixed ball-retaining race 34 mounted between the gear 22 and the nut 26. The race 34 has a flat annular portion 36 which terminates in an annular lip 38. A spring-biased, second ball-retaining race 40 having an axial pin section 42 axially, slidably mounted in the cam shaft bore 32 cooperates with the race 34 in retaining a series of balls 44 between them and around the shaft 14. The race 40 has a fru-sto-conical section 46 in abutment with the balls 44 so that the balls move under the influence of centrifugal force between radial positions corresponding to different rotational velocities of the cam shaft 14 with the race 40 assuming axial positions corresponding to the radial positions of the balls. The race 40 carries an axially directed pin 48 engaged in a cavity of a gear cover 50 so that the race 40 cannot rotate relative to the fixed race 34.

A drive plate 51 locked on the shaft 14 by nut 26 is slotted to engage each of the balls 44 so that the balls rotate with the cam shaft.

The master cylinder assembly 12 comprises a cupshaped housing member 52 mounted by a series of threaded fasteners 54 to the end of the gear cover 50 to form a fluid chamber 56. The housing member 52 has an annular recess 58 facing its mounting surface on the gear cover 50.

An annular piston member 60 fixedly attached to the moveable race 40 extends into the chamber 56 and has an annular recess 62 for receiving the enlarged end of a flexible, rolling diaphragm 64. The diaphragm is attached to the piston 60 by an annular retainer 66 and its opposite enlarged end is retained in the annular recess 58 of the housing member 52 so that it provides a fluid tight seal between the piston 60 and the housing member 52. It is to be noted that the piston 60 has a lesser diameter than the circular aperture 67 of the gear cover through which the piston member 60 extends so that the flexible diaphragm 64 provides a rolling seal between the housing member 52 and the piston 60. The rolling diaphragm 64 eliminates the friction commonly associated with sliding type seals, provides positive sealing and has extremely low hysteresis losses.

A threaded adjusting member 68 is mounted in the fluid chamber 56 with its end seated in a recess 70 in the housing 52. An adjusting nut 72 mounted on the threaded member 68 has a spherical portion 74 pointed toward the end of the cam shaft 14. A spring retainer 76 has a spherical seat 75 engaged with the spherical portion 74 of the nut providing means for retaining the end of a compression spring 78 which acts between the retainer 76 and the movable race 40. The spherical seat 75 has a greater radius than the spherical portion 74 of the nut to compensate for variations in alignment of the spring 78. The nut has a length greater than one-half the normal distance between the ends of the spring 78 to provide better control in positioning the spring.

The spring 78 provides an axial force urging the movable race 40 toward the fixed race 34 so that the two races are at all times in abutment with the balls 44. Thus when the balls 44 move radially outwardly under an increase in the rotational velocity of the cam shaft 14, the balls force the movable race 40 away from the fixed race 34, and when the rotational velocity of the cam shaft decreases, the frusto-conical portion 46 of the movable race 40 under the influence of the spring 78 causes the balls to move radially inwardly to a position where the radial force produced on the balls 44 by the race 40 and the centrifugal forces of rotation are balanced. The extreme outward position of the balls 44 is limited by the lip 38 of the fixed race.

In order to vary the tension of the spring 78 on the race 40, a crown gear 80 fixedly attached to the threaded member 68 has an annular array of teeth in mesh with an adjusting gear 82 carried within the chamber 56 and on the end of an adjusting screw 84. The adjusting screw 84 is sealingly mounted for rotation on the housing 52 about an axis at right angles to the axis of travel of the nut 72. The adjusting screw 84 carries a pair of sealing O-rings 86 and permits the operator to rotate the threaded member 68 through the cooperating gears so that the nut 72 applies a predetermined tension on the spring 78.

Thus, the operator can externally adjust the tension of the spring 78 and thereby vary the magnitude of the speed change associated with a given change in volume of the chamber 56. As the race 40 reduces the volume of the chamber 56 under the influence of the outwardly moving balls 44, hydraulic fluid in the chamber is forced through the conduit 16 (FIG. 2) to the slave unit 18. The slave unit 18 is mounted on the engine 86 and comprises a cylindrical member 88 closed by a head member 90 which is connected through a union 92 to the conduit 16. A piston 94 mounted for reciprocation within the head member 90 forms a fluid chamber 96 fluidly connected by the conduit 16 to the chamber 56. A rod 98 which moves with the piston 94 is pivotally connected by a link member 100 to the throttle valve member 20, so that a motion of the piston 94 caused by an expansion or contraction of the volume of the chamber 56 is transferred to the member 20.

A rolling diaphragm 102 having one end retained in an annular recess 104 of the cover 90 and its opposite end retained by a retainer 106 joined to the rod 98 and a nut 108 mounted on the retainer 106 provides a fluid seal between the cover 90 and the piston 94. The diaphragm 102 provides a fluid tight seal without the friction associated with the wiping action of conventional piston seals and, in addition, exhibits very low hysteresis losses. A spring member 107 acting between the piston 102 and the engine mounting surface produces a force on the piston tending to reduce the size of the chamber 96 so that when the chamber 56 in the master cylinder is enlarged by movement of the race 40, the chamber 96 is correspondingly reduced in volume with the pistons 94 and the race 40 moving in unison.

A plug 110 provides means for introducing hydraulic fluid into the system through the slave unit 18 and a plug 112 provides means for introducing hydraulic fluid into the system through the master cylinder 12.

It can therefore be seen that I have described in detail a novel hydraulic governor system for internal combustion engines which employs a pair of cooperating races for retaining centrifugally actuated balls, one of the races acting as a pumping member in a master hydraulic cylinder. A closed hydraulic pressure column connects the master cylinder to a slave unit operatively connected to an engine control member such as the throttle valve member or a carburetor control member. The preferred system employs rolling diaphragms between each piston and its cylinder to reduce the overall friction of the system and to provide positive sealing. The hydraulic lines eliminate external levers and tampering with the system and the novel gear arrangement for adjusting the sensitivity of the unit eliminates internal levers and bushings to further reduce friction losses in the systems.

Preferably the governor is adjusted when the engine has been fully warmed up so that variations in the governors operation are reduced to a minimum. The hydraulic fluid in the system is preferably a low-30 oil or silicon fluid to accommodate extreme cold weather operations.

Having described my invention, I claim:

1. A governor system for an internal combustion engine having a rotatable shaft and a movable control member, comprising:

(a) a plurality of actuating balls;

(b) a pair of cooperating ball races adapted to be mounted on said rotatable shaft to support said balls between said races for movement between radial positions relative to the axis of rotation of said rotatable shaft, means restricting one of said races against axial movement and means supporting the second of said races for axial movement;

(0) spring bias means on said engine for urging the axially movable race toward the axially restricted race;

(d) one of said races having a surface with a predetermined contour in abutment with said balls so that radial movement of said balls under the-influence of centrifugal forces produces axial displacement of said axially movable race;

(e) housing means adapted to be mounted on said engine forming a fluid chamber bounded on one side by the axially movable race so that axial movement of the axially movable race varies the volume of said fluid chamber; and

(f) fluid control means adapted to provide a connection between said chamber and said movable control member and adapted to move said control member as the volume of said fiuid chamber varies.

2. A governor system as defined in claim 1, including means for applying a predetermined bias on the axially movable race to control the change in the magnitude of the centrifugal forces acting on said balls necessary to move said balls between first and second radial positions.

.3. A governor system as defined in claim 1, wherein said bias means comprises a threaded member mounted in said chamber and adapted to form an extension of the axis of rotation of said rotatable shaft, means rotatably mounted on said threaded member, and axially spaced from said movable race, a spring mounted between said nut means and said movable race to urge said axially movable race toward said axially restricted race, and means producing relative rotation between said nut means and said threaded member so as to vary the axial force said spring applies on said axially movable race.

4. A governor system as defined in claim 3, wherein said last mentioned means comprises a first gear member fixedly mounted on said threaded member within said chamber, said first gear member having an annular series of teeth, an adjusting screw mounted on said housing means for rotation about an axis at right angles to the axis of motion of said nut means and adapted so an operator can rotate said screw by applying a force exteriorly of said chamber, a second gear carried on the inner end of said adjusting screw in mesh with the teeth of said first gear so that rotation of said adjusting screw rotates said threaded member to vary the distance between said nut means and said axially movable race.

5. A governor system as defined in claim 1, wherein said fluid control means comprises second housing means adapted to be mounted on said engine forming a second fluid chamber, a piston mounted in said second housing means to form a movable wall of said second fluid chamber, said piston being movable in response to fluid being pumped into said second fluid chamber, means providing a fluid connection between the fluid chamber of said first mentioned housing and said second fluid chamber, motion-transmitting fluid in said chambers and said fluid connection so that axial displacement of said axially movable race produces a corresponding movement of the piston in said seond chamber, and linkage means adapted to correct said piston and said control member so that radial movement of said balls under the influence of changing centrifugal forces acting on said balls produces a corresponding movement of said control member.

6. A governor system as defined in claim 1, wherein said axially movable race has a frusto-conical surface in abutment with said balls so that the axial displacement of said movable race relative to said axially restricted race varies as a function of the radial displacement of said balls.

7. A governor system as defined in claim 1, wherein said fluid control means comprises a second housing means having a cylinder forming a part of a second fluid chamber, a piston reciprocally mounted in said second fluid chamber and adapted to move in response to the introduction of fluid into said second fluid chamber, said piston having a diameter less than the sidewalls of said cylinder so as to form an annular clearance between said piston and said cylinder, and a rolling flexible diaphragm carried by said piston and said cylinder to provide a fluid seal between said piston and said cylinder.

References Cited UNITED STATES PATENTS 2,292,805 8/1942 Tippen l23--l08 2,733,690 2/1956 Adler 91458 X 3,365,016 1/1968 Breck 91-458 X JAMES W. WESTHAVER, Primary Examiner US. Cl. X.R. 91366; 123-108 UNITED S'lA'lES PA'lENT OFFICE CEH'LIFICA'IE OF CORRECTION Patent No, 3,468,223 Dated Sept. 23, 1969 Invcntor(s) QAKLAN 1; m:

lt is certified that error appears in the above-identified patent anu LucL said Letters Patent are hereby corrected as shown below:

Column 3, line 7, should be deleted and replaced with rotational velocity of the camshaft 14 produces an adline 14, "relation" should be relative and l4 should be inserted after "shaft" Claim 5, column 6, line 22 "correct" should be connect \JH all fun) fiEALED FEB 1 71970 (SEAL) Am Edward m. Fletcher, Ir. n-mu n. m.

Anesfing Officer Commissioner of Patents

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