US2786668A - Centrifugal governor - Google Patents

Description

March 26, 1957 H. G. ADLER CENTRIFUGAL GOVERNOR 2 Sheets-Sheet l Filed April 30 1951 March 26, 1957 Filed April 30 1951 H. G. ADLER CENTRIF'UGAL GOVERNOR 2 Sheets-Sheet 2 FIG.4. 52

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l 5 l 'l JNVENTOR.

HERMAN G.ADLER BY Wmv,

ATTORNEYS CENTRIFUGAL GOVERNOR Herman G. Adler, Detroit, Mich., assignor to Novi Equipment Company, Novi, Mich., a corporation of Michigan Application April 3i), 1951, Serial No. 223,792

11 Claims. (Cl. 264-17) The present invention relates to a governor and more particularly, to a centrifugal type governor for us-e in controlling the speed of an internal combustion engine.

It is an object of the present invention to provide a governor characterized by its quick response and to low hysteresis characteristics upon application and removal of loads.

It is a further object of the present invention to provide a governor including centrifugal elements adapted to spin at high speeds in such a relationship that forces applied thereto resulting from changes in speed produce a precessive force in a direction to assist the usual centrifugal movement of the elements.

lt is a further object of the present invention to provide a centrifugal governor including a radially slotted driver, a ball race associated with said driver and balls adapted to be retained in the slots by engagement between the side edges of the slot and the ball race, the driver being sufficiently resilient to permit the balls to be snapped into place to complete a subassembly. v

lt is a further object of the present invention to pronited States Patent O vide a governor comprising a rotatable member adapted n to be shifted axially in accordance with engine speed, said member including an eccentric projection, in combination with a lever engaging said member and adapted to be vibrated at high speed with small amplitude by rotation of the eccentric projection.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying draw# ings, wherein:

Figure 1 is an end view of the governor assemblywith the governor lever omitted for clarity. v

Figure 2 is a section on the line 2 2, Figure l, the governor lever being included in this view.

Figure 3 is an end view of the sub-assembly comprising the driver, ball race, and centrifugal balls.

Figure 4 is a section on the line 4-4, Figure 3.

Figure 5 is an enlarged section on the line 5 5, Figure 4.

Figure 6 is a fragmentary side elevation tor pin used in the governor.

Referring now to Figures l and 2, the governor is adapted to be mounted in conjunction with a cam shaft and cam shaft gear, the cam shaft being shown at 10 and the cam shaft gear being shown at 12. The end of the cam shaft is provided with an elongated recess 13 to receive a stub shaft 14 having an elongated axially extending slot 16 formed along one side thereof. The stub shaft 14 has a longitudinally extending opening 18 therethrough. The end of the cam shaft 10 is of reduced cross-section as indicated at 20, and is provided with a pin receiving opening 22 extending therethrough. A pin 23 is received in the opening 22 and extends into the slot 16 so as to key the stub shaft 14 to the cam vshaft 10 for rotation therewith while permitting movement of the stub shaft longitudinally of the cam shaft.

`of an oscilla- ICC The governor includes a sub-assembly best illustrated in Figures 3, 4, and 5, which includes a driver indicated generally at 24, a retainer indicated generally at 26, and an inner ball race indicated generally at 28. The driver is formed of sheet metal suiiciently thin to provide a certain amount of transverse resilience but which is substantially rigid with reference to forces applied in the plane thereof. The driver 24 includes a central cupped portion 3i) having a central opening 32 provided with a keyway 34 by which it is keyed to the shaft 10. The edge of the driver is provided with radial slots 36 which extend to the periphery of the driver. As best seen in Figure 5, the slots 36 include laterally extending oblique flanges 38 which as shown in the figure, extend at an angle of about l2 degrees from planes perpendicular to the general plane to the driver. The slots 36 and particularly the flanges 38 thereof, are dimensioned so that the transverse width of the slots is slightly less than the diameter of the centrifugal balls 40 received in the slots.

The retainer 26 includes a central cupped portion 42 dimensioned to it snugly within the cupped portion 30 of the driver and is provided with a central opening 44 and a keyway which registers with the keyway 34 provided in the driver. The retainer 26 includes a radially outwardly extending peripheral ange 46.

The inner ball race 28 is generally annular in shape and includes a tubular collar 48 dimensioned to fit snugly over the outside of the cupped portion of the retainer 26. Outwardly from the collar 48 the ball race extends generally radially and includes a llat ball engaging surface 50. Adjacent the periphery of the ball race 28 there is provided an angularly turned edge portion 52 which in the assembly extends toward the driver 24. The parts are so proportioned that the ball 40 in the position shown in Figure 4, is in engagement with the edges or flange portions 38 of the slots and with the flat or plane surface 50 of the ball race. The balls are thus freely movable radially -of the slots 36. However, as the balls approach the outer open end of the slots they engage the angularly turned edge portions 52 of the ball race and are thus retained against moving out of the slots. However, as previously stated, the material from which the driver is formed is sheet metal of such gauge as to be somewhat resilient and thus displaceable transversely of the plane thereof. Accordingly, the balls 40 may be removed from the slots by the application of suicient pressure to bend the tongues 54 intermediate the slots 36. At the same time, the balls may be inserted by the reverse action. Thus, the balls may be snapped into or out of assembly but will be retained in the assembly against gravitational or other light forces.

In completing the sub-assembly shown in Figures 3-5, the ball race 28 is assembled over the cupped portion 42 of the retainer and the cup shaped portion 42 of the retainer is inserted into the cup shaped portion 3i) of the driver. This centralizes the ball race with reference to the driver. The cup shaped portions 30 and 42 are then flush riveted as indicated at 56. Thereafter, the balls 40 may be snapped into the slots 36 where they will be resiliently retained. This subassernbly greatly facilitates production of the item since the problem of inserting a larger number of balls in slotted members during assembly has Aalways presented somewhat of a problem. In the present case a complete sub-assembly is easily produced in which the balls are retained and the sub-assembly is inserted in the complete assembly as will now be described.

The `sub-assembly including the driver 24, the retainer 26, the inner race 28, and the balls 40, is assembled over the reduced end 58 of the cam shaft 10, the reduced end portion of the cam shaft including a key received in the vkeyways provided at th-e central openings 32 and 44 of the driver .and netainer. Thus, the sub-assembly is keyed against rotation relative to the cam shaft and is adapted to be driven thereby. The sub-assembly is retained in assembled position by a nut 60 carried by the threaded outer end of the reduced portion 53 of the cam shaft.

The outer end of the stub shaft 14 is reduced as indicated at 62 and sleeved over the reduced portion 62 of the stub shaft is a bushing 64 having a radially outwardly extending flange 66 and an inclined surface 63 for engagement with ball bearings 70. The bushing 64 carries the outer ball race 72, the ball race 72 having a central opening surrounding the stub shaft and surfaces engaging the inner surface of the iiange 66. The bushing 6,4 and outer ball race 72 are permanently Connected together such for example as hydrogen brazing, as indicated at 74. Adjacent its periphery the race 72 includes a centrally shaped portion 76 having an inner ball engaging surface 78 which extends toward the plane ball engaging surface 50 of the inner race 28. Thus, the inner and outer races together define an outwardly narrowing or converging space for coaction with the balls 40.

The bushing 64 is relatively rotatable with respect to the stub shaft 14.

Located within the outer open end of the stub shaft 14 is an oscillator pin 82, details of which are best seen in Figure 6. The oscillator pin 32 includes a reduced portion 84 pressed into the outer open end of the stub shaft 14, an enlarged portion S6 providing a shoulder S3 engageable with the outer end of the stub shaft 14, and an oscillator portion 901. The oscillator portion Et includes a at end surface 92 having a high point 94 located eccentrically with respect to the axis of the oscillator pin. The head of the pin 82 extends outwardly to provide an annular shoulder 96 which engages the ball bearings 70, thus providing for substantially free relative rotation between the oscillator pin S2 and the bushing 64.

The governor includes a governor lever 100 carried by la pivot support 102, and a contnol lever 104 which is adapted to be rocked about the pivot axis of the support 102, in accordance with rocking movement of the governor lever 160. A suitable spring 100 is connected into the system so as to apply a counterclockwise force to the governor lever 100, thus causing the governor lever to bear against the outer end of the oscillator pin S2, the pin 82 constituting an abutment for rocking lever 100. As is usual, means .are provided for varying the effectiveness of the spring so as to control the operation of the governor.

Forces applied through the governor lever i? to the pin are transmitted from the pin through the bearings 70 to the bushing 64 and outer ball race 72 thus pressing the outer race firmly against the centrifugal balls 40. The outer race 72 is provided with an outstanding projection 106 which is conveniently formed by stamping the projection out of the material of the outer race, thereby leaving an opening 1% therethrough. The projection 106 is engageable with the governor lever 100 and thereby prevents rotation of the outer race 72.

In operation, rotation of the cam shaft 10 is transmitted directly to the sub-assembly including the driver 24, retainer 26, race 28, and centrifugal balls 40. Moreover, this sub-assembly is retained against axial movement by the nut 60. lt will be observed however, that the inner race 28 is not clamped Iirmly between the driver 24 and the ilange 46 of the retainer 26. The support thus imparted to the inner race is frictional only. in use of the device, further forces applied through the balls to the inner race press the inner race into frictional Contact with a web 110 of the cam shaft gear 12. However, during continued operation of the governor, the inner race ZS creeps relative to the driver 24 and the balls 40 so that the action of the balls 40 is distributed generally over the entire ball engaging surface 0 of the inner ball race 28.

As the driver 24 and inner race 28 are rotated, this rotation is of course imparted to the balls 40 and centrifugal forces developed by rotation of the balls tends to cause the balls to move radially outwardly against the inclined ball engaging surface 73 of the outer race 72. This causes the outer race 72 to move to the left as seen in Figure 2, carrying with it the bushing 64 and the oscillator pin 82. The pin 82 is pressed firmly within the opening in the stub shaft 14 and `accordingly the entire stub shaft moves to the left with the outer race 72. However, the outer race 72 is retained against rotation by engagement between the projection 106 and the lever 100. On the other hand, rotation is positively imparted to the stub shaft 14 by the pin 24 and this rotation is also imparted to the oscillator pin 82 through the press tit with which the oscillator pin is assembled to the stub shaft 14.

The forces developed by the governor spring 101.' oppose movement of the outer race '72 to the left and hence oppose radially outward movement of the balls 40.

Accordingly, the balls will move out to a radius dependent upon the adjustment of the governor' spring and the speed of rotation ofthe cam shaft.

Due to the presence of the eccentric high point 94 on the oscillator pin 82, a slight but rapid vibration or oscillation will be imparted to the governor lever 106 and hence to the control lever 104. This has the effect of rendering the governor less sluggish in its response to changes in speed and has the further effect of substantially reducing the hysteresis upon application and removal of loads.

The action of the governor is further improved by a very important gyroscopic action which will now be described. The balls 40 tend to roll against the engaging surfaces where such action is possible and by the arrangement of ball engaging surfaces of the races and the con struction of the ball receiving slots of the driver, the balls 40 are caused to spin about axes passing centrally therethrough as indicated at 112. With the arrangement illustrated in Figure 2, the axes 112 about which the balls spin are substantially parallel to the axis of revolution of the balls about the cam shaft. The balls 40 engage the inclined surface 78 of the outer race at a point 114 and rotation of the balls 40 about the axis 112 results in the balls rolling against the surface 78 and establishing a small circle of contact 116. At the same time, the balls engage the plane surface of the inner race 28 at points 11.8 through which the axis 112 passes. Accordingly, the balls spin about the point of contact on the plane surface 80.

Assuming that the inner race 2S and driver 24 in Figure 2, are rotating in such direction that the lowerniost ball 40 is moving toward the observer, the ball 40 is spun rapidly in a direction indicated by the arrow 120. Furthermore, the rate of spin olf the ball is extremely high, being on the order of ten times as 'fast as the rotational. speed of the cam shaft. In practice, the balls are observed to spin at speeds on the order of 10,000 R. P. M.

This extremely high rate of spin of the balls 40 is suflcient to develop very appreciable gyroscopic forces. Moreover, as will be apparent, these forces are in a direction such that as yforces of acceleration are applied to the balls (as a result of increase in speed of the governed engine) these accelerating forces tend to cause the balls to move radially outwardly of their circular array by gyroscopic precession. Conversely, forces applied to the balls tending to decelerate the balls (as a result of decrease in speed of the governed engine) establish pre` cessional forces tending to move the balls radially inwardly. Thus it is seen that the gyroscopic action of the balls tends to establish precessional forces upon increase or decrease in engine speed which are in a direction to assist the normal centrifugal forces developed thereby. Moreover, response to the governor is rendered substantially instantaneous due to the fact that the precessional forces are developed instantaneously upon application of accelerating or decelerating forces independent of radial inward or outward motion of the balls resulting from purely centrifugal forces. Depending upon the mass of the individual balls 40 and the rate of spin imparted thereto, the precessional forces thus developed may be quite significant and will result in a sensitivity of the governor far exceeding anything which could be obtained without taking advantage of the gyroscopic action of the balls.

It is found that although the balls spin at extremely high rates of speed, the governor constructed in accordance with the foregoing is not subject to appreciable wear as a result of such spin. One reason for this of course is the fact that the balls actually roll on the inclined ball engaging surface 78. Moreover, while the balls spin in contact with the plane ball engaging surface 80, there is a constant shifting of the point of contact between the balls and the surface 80 in use. This of course is due to the fact that the race 28 is not keyed for rotation with the driver, but yis merely frictionally associated therewith. In practice, it is found that a very substantial amount of creep inherently results from the construction described and that no significant areas of wear develop on the ball engaging surfaces of either race.

While the construction illustrated and described in detail results in a spinning action of the balls 40 about axes substantially parallel -to the axis of the cam shaft 10, a different arrangement of ball engaging surfaces may be employed with the result that the axis of spins of the balls may be angularly related to the axis of the cam shaft 10. In any case however, gyroscopic forces will be developed which will have a component additive to changes in centrifugal force developed by acceleration or deceleration. In general, it may be said that the ball races should be designed so that the axis of spins of the balls 40 forms a minor angle, or an angle of less than 45 degrees, to the axis of the cam shaft 10.

The present governor is characterized by its extreme simplicity and the economy with which it may be manufactured. It is further characterized by its reduced hysteresis and its quick response to changes in engine speed. Assembly of the governor is substantially facilitated by the design of the sub-assembly compression, the driver, retainer, inner race and balls. Moreover, the provision of the rotating oscillator pin in contact with the governor lever further increases the sensitivity of the governor and improves its overall operating characteristics.

The drawings and the foregoing specification constitute a description of the improved centrifugal governor in such full, clear, concise and exact terms as to enable any person skilled in the art .to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

l. In a governor, a sub-assembly comprising a peripherally radially slotted rota-ry driver formed of sheet metal, balls partially received in said slots, said slots being slightly narrower than 4the diameter of said balls, a ball race secured to said driver, said race having a flat surface perpendicular to the axis of rotation of said driver throughout the major portion thereof opposite the slots in said driver, the peripheral edge of said race extending toward said driver, said balls being retained in said slots by engagement with the edges of said slots and with said race, the peripheral portions of said driver intermediate said slots being flexibly displaceable to permit snapping said balls into said slots.

2. Struc-ture as defined in claim l in which said driver has a cupped central portion, a retainer having a cupped central portion intertitting with the cupped central portion of the driver and having a peripheral radial flange, and said ball race has an inner portion located between said radial flange and said driver.

3. Structure as defined in claim 2 in which said cupped portions are of relatively great difference in depth providing a cylindrical bearing surface between the slotted peripheral portion of said driver and the flange of said retainer, and said race has a cylindrical sleeve supported on said bearing surface.

4. A governor comprising a shaft, a recess in the end of said shaft, a stub shaft in said recess, key means driving said stub shaft in rotation and providing for axial movement of said stub shaft in said recess, a driver keyed to said shaft having radial slots therein, a ball race carried by said shaft and normally rotatable therewith, an abutment at the outer end of said stub shaft, a second ball race relatively rotatably mounted on said stub shaft and axially movable therewith, balls in said slots, a governor lever bearing against said abutment, a spring connected to said lever, and a stop on said second ball race engaging said lever to prevent rotation of said second race.

5. Structure as defined in claim 4, said abutment comprising an eccentric portion adapted to vibrate said lever.

6. Structure as defined in claim 4, said races engaging non-diametrically related points on each of said balls to impart a high rate of spin thereto about an axis passing centrally lthrough said ball and generally parallel to the axis of rotation of said shaft to develop gyroscopic forces assisting centrifugal forces in radial movement of said balls.

7. In a governor, a sub-assembly comprising a peripherally radially slotted rotary driver, balls partially received in said slots, said slots being slightly narrower than the diameter of said balls, said driver having an annular, axially extending, central flange, a retainer having a cylindrical portion fitting within said central flange and having a peripheral radial flange spaced from the slotted portion of said driver to provide a cylindrical bearing surface between the slotted peripheral portion of said driver and the flange of said retainer, and a ball race located at one side of said driver and coaxial with the latter, said ball race having an annular, axially extending, central flange supported on said cylindrical bearing surface, said balls being retained in said slots by engagement with the edges of said slots and with said race. v

8. In a governor', a sub-assembly comprising a ball race race having a smooth annular ball engaging surface, an annular driver having peripheral generally radially extending lingers defining ball receiving slots therebetween, said fingers being flexibly movable toward and away from said race but effectively rigid in opposing operating forces applied in the plane of said driver, means connecting said driver and race together in concentric axially spaced relation, a ball partly received in each of the slots of said driver and disposed between said driver and race, said slots being slightly narrower than said balls whereby said balls are retained in position by said fingers and race and said fingers are engageable with said balls adjacent opposite sides of a diametral plane, the peripheral edge of said race being inclined toward said driver to prevent introduction or removal of a ball to or from said sub-assembly except by exure of said lingers away from said race.

9. In a governor, a sub-assembly comprising a peripherally radially slotted rotary driver, balls partially received in said slots, said slots being slightly narrower than the diameter of said balls, said driver having a cupped central portion, a retainer having a cupped central portion interlitting with the cupped central portion of said driver and having a peripheral radial flange spaced from said driver, and a ball race having an inner portion located between the Slotted portion of said driver and the radial ange of said retainer and secured to the lat-ter, said balls being retained in said slots by engagement with the edges of said slots and with said race.

10. Structure as defined in claim 9, the peripheral portions of said driver intermediate said slots being ilexibly displaceable to permit snapping said balls into said slots.

References Cited in the ile of this patent UNITED STATES PATENTS Schacht Apr.

8 Balou-gh Apr. 27, Balough Oct. 2, Dina Oct. 7, Walker Dec. 4,

FOREIGN 'PATENTS Germany Mar. 26, Switzerland Sept. 16, Great Britain Dec. 8, Germany July 2.2,

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