US3073178A

US3073178A - Adjustable eccentric drive devices

Info

Publication number: US3073178A
Application number: US799302A
Authority: US
Inventors: William E Barnes; Zubaty Joseph
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1959-03-13
Filing date: 1959-03-13
Publication date: 1963-01-15
Anticipated expiration: 1980-01-15

Description

7 Jan. 15, 1963 w BARNES ETAL I 3,073,178

ADJUSTABLE ECCENTRIC DRIVE DEVICES Filed March 13, 1959 2 Sheets-Sheet 1 INVENTORS ATTORNEY .Jan. 15, 1963 w. E. BARNES ETAL ADJUSTABLE ECCENTRIC DRIVE DEVICES 2 Sheets-Sheet 2 Fild March 15, 1959 Z2 INVENTORS' If/25962222 (5 567276: {$36 5 3,073,??? Patented Jan. 15, 1953 This invention relates to devices suitable for driving pumps and more particularly to adjustable eccentric drive devices for pumps suiting the needs of variable speed engines with respect to quantity and pressure of liquid fuel supplied.

The displacement of a liquid fuel pump should be in accordance with engine need which will vary as the engine speed and the engine load varies. The control of fuel pump discharge volume by utilizing engine manifold vacuum is a known expedient. Also, the automatic control of pump discharge pressure by use of a valve controlled bypass line is conventional. There are advantages in controlling the fuel pump output by combining the engine manifold vacuum control and the fuel pressure control in a self-contained or single pump unit. These advantages are not obtained, to the extent desired, in either manifold vacuum control or fuel pressure control used alone. For instance, when the engine throttle is wide open no control of the fuel pump output is available relative to engine speed. Pressure of the fuel, however, will serve in this connection. Also, at low engine speeds, the fuel pressure may be and is usually ineffective as a control but a control by engine manifold vacuum is quite sensitive.

An object of the present invention is to provide an im proved drive device suitable to actuate a fuel pump the output of which is automatically controlled in accordance with the demand of the engine being served.

To this end, a feature of the present invention is an adjustable eccentric drive device for a fuel pump and which may be automatically controlied by engine manifold vacuum and also by the pressure of fuel on the discharge side of the pump. Another feature of the invention is an adjustable eccentric drive device having cam means for varying displacement or eccentric throw in accordance with two pressure conditions such as the fuel pressure demand of an engine and the load placed on the latter as evidenced by manifold vacuum.

These and other important features of the invention will be described in detail in the specification and then pointed out more particularly in the appended claims.

in the drawings:

FIGURE 1 is a sectional view through portions of a fuel pump showing an eccentric drive device as an embodiment of the invention, other portions being broken away to present structural details;

FIGURE 2 is a sectional view looking in the direction of the arrows 2-2 in FIGURE 1; and

FIGURE 3 is a sectional view of portions of the eccentric device and looking in the direction of the arrows 3-3 in FIGURE 1.

In the drawings, the pump housing is generally indicated at it). This housing includes a main body 12, a top cover 14, a bottom cover 16 and

intermediate portions

18, 2t and 22. interposed between the main body 12 and the bottom cover 16 is another body member 26, a portion of which extends up into a cavity 27 formed in the body 12. This cavity is reduced in diameter at its upper portion 27.

A supplementary casing is generally indicated at 28.

- This casing is to one side of the main housing 10 and comprises an exterior plate 34 and an interior plate 32.

The top cover 14 of the pump housing includes a threaded inlet indicated at 34 which communicates by means of a port 36 with a roughly U-shaped channel 38 formed in the bottom face of the cover. The cover 14 also has a threaded fuel outlet 40 which communicates by means of an outlet port 42 with an opening 44 formed in the housing portion 18. This port, in turn, communicates with a channel 46 of five interconnected straight runs and formed in the lower face of the housing portion 18 as best seen in FIGURE 7. A gasket 48 is interposed between the housing portions 14 and id but which is apertured to provide the requisite communication with the inlet and outlet ports 34 and 40 and also to circumscribe one end of a hollow boss 50 which is an integral part of the housing portion 22. The top cover 14 bears a recess 54 for the reception of the extreme end of the boss 50.

Five intake ports 56 leading from the channel 38 in the cover 14 are formed in the housing portion 18 and communicating with each of these is a cylindrical recess 58 formed in the lower face of the housing portion 18. The bottom surface defining each recess 53 is annularly grooved at 6% (FIGURE 1) for the retention of an O-ring 62. A button-type nylon valve disk 64 is urged against each O-ring 62 to close the corresponding inlet port 56. The urging is performed by a metallic leaf spring 65. There are five of these inlet leaf springs 66 and five similar outlet springs 67 and all ten are integral with a sheet 68 of resilient metal. The leaf springs 66 serve five inet valves 64 and the leaf springs s7 serve five outlet valves 7 ti but urge them in the opposite direction. These valves 70 engage O-rings '73 and serve to control ports 72 formed in the housing portion 20. Each port 72 connects with the outlet channel 46 as will be understood. The spring sheet 68 is interposed between two sealing gaskets 78 and 80 which in turn form a tight joint between the

housing portions

18 and 20. These sealing gaskets are'pierced to register with inlet and outlet passages and surround the boss 54 The main body 12 of the housing has an upstanding central portion a horizontal cross section of which is fivesided. Fixed to this side by means of four screws 84 and spring washers S6 is a cover plate 3% and an intermediate plate Bft. The cover plate 3% is recessed at 92 to form part of a pumping chamber. The intermediate plate 9% is apertured at 94 to form a cylindrical portion of the pumping chamber and also at 96 and 97 to form lengths of inlet and outlet passages 98 and 99 which extend by way of ports 190 and M1 in the housing portion 22 to the intake and outlet valves 64 and iii. A gasket m2 is interposed between the cover 88 and the intermediate cover 91 and a special diaphragm 104 traverses the pumping chamber portion 94 and has an extension of reduced thickness which serves to form a seal between the intermittent cover fit and the main body 12. A gasket res is also provided between the top of the main body 12 and the housing portion 22.

Five cylinder linings Hi8 are inserted in the main portion 12 and each defines a bore 116 which registers with a pumping chamber portion 94 on the opposite side of a corresponding diaphragm 104. A nylon plunger H2 is reciprocably mounted in each bore with one end in contact with the diaphragm 1M and the other end being curved as at 114 for contact with a multiple ring arrangement generally indicated at 116 and located in the upper cavity portion 27. It will be understood that for each cover plate 38 there is a plunger 112 in engagement with the ring arrangement 116i.e.-there are five radialiy arranged cylinders or bores lit) in which the five plungers and through the passage 146 and is connected to phragm 130 with the aid of two diaphragm backing plates in the housing portion 22. .208 bears a tongue 216 to facilitate its connection with a 122 (FIGURE 1), gaskets 124 and 126 forming the appropriate seals. As for the supplementary casing 28, it is held by bolts 128, some of which are of sufiicient length to enter the main body 12. A gasket 130 is interposed between the two plates 3% and 32 and another gasket 132 is used between the plate 32 and the main body 12. A threaded opening 134 is made in the bottom cover 16 which opening is used to connect with a threaded support bolt (not shown) for holding the pump in position. There is also an opening in the cover 16 for the admission of lubricating oil which may be introduced under low pressure. This opening is disclosed at 136 and it, of course, registers with a required opening 138 in the plate 26. This passage, thus provided, introduces oil under low pressure for lubrication purposes and return of the oil to the engine crankcase is by an opening to be described hereafter.-

The outside plate 311 of the supplementary casing 28 is formed with a chamber 140 partially defined by the diaphragm 130. This chamber is adapted to be connected with an intake manifold of an engine by means of a threaded port 142. The inner plate 32 is also chambered as at 142 in registry with the chamber 140 and the chamber 142 communicates with the chamber 27 of the main housing portion 12 by means of a port 144 (FIGURE 2) formed in the'plate 32 and an opening 146 formed in the portion 12. A rod 148 extends from the chamber 27 the dia- 150 and 152. The rod 148 is peened over at 154 to clamp the backing plates and diaphragm tightly together.

The plates 30 and 32 chambers 156 and 158 (FIGURE 2). These chambers are separated by a diaphragm 160 and a nylon plunger 162 slidably mounted in the chamber 158. A threaded connection 161) is formed in the plate 30 for communication with the pressure discharge line of the pump. The plunger 162 is centrally recessed at 164 for the reception of one end of a short plunger 166. The latter extends into the housing portion 12 and is slotted as at 168 to receive a link 170. The latter is longitudinally slotted as at 172 to receive a pin 174. Extending from near one end of the link 171) is a projection 176 which contacts the center of a spring retaining plate 178. The latter bears against the end of a coiled spring 186 which is'retained in the housing portion 12 by means of a partially cylindrical wall 182 formed in the latter and a screw plug 184 which bears against the other end of the spring. The plug 184 may be turned in or out of the housing portion 12 to modify the loading of the spring 180 as will be understood.

The intermediate portion of the link 17 is pivoted on a pin 186 which in turn is fixed to a forked projection 138 forming a part of the plate 32 and extending into the housing portion 12. The other end of the link 170 is forked as at 191) and'pivoted on a pin 192 which passes through an intermediate portion of the rod 148. The end of the latter as located within the chamber 27 is pivoted plate 196 The pivoting is by means of a pin 193 and the latter is held by means of a cotter pin 2%. The plate 196 is held to a cuplike cam plate 202 by means of screws 204. n g

- In alignment with the boss 50 is a drive shaft 208. The

upper end of the latteris' reduced slightly as at 211% (FIGURE 1) for retention Within a roller bearing 212 the outer race of whichis held within a recess 214 formed The other end of the shaft rotary driving member such as an accessory or some part of an engine. This end ofthe shaft extends through an opening 218 formed inthe bottom plate 16 and through which lubricating oil is returned to the engine crankcase.

, This spring also is part of a vent for the chamber142. plate '16 is also formed to support a roller bearing also hear smaller and registering to a projection 194 extending from an annular 221} in which the shaft 2% is adapted to rotate. The plate 196 and the cam member 2132 are free to rotate together on the shaft 298 and they are supported on the inner face of the housing plate 26 by means of three roller bearings 222. Each of the latter is held on a short shaft 224 resting in a recess 226 formed in the upper face of the plate 26. The cam plate 282 has three notches 228 formed in its depending wall and the arrangement is such that the three roller bearings may enter the notches to a varying degree dependent upon the relative rotative position of the cam plate 2ll2 with respect to the housing plate 25. The contour of each notch 228 is best seen in FIGURE 3.

A needle or roller bearing arrangement 23% surrounds the shaft 26% and is interposed between the plate 196 and a hub 232 which forms part of the ring arrangement 116 heretofore referred to. This hub 232 is free to rotate with respect to the shaft 208 and supports a ring or cylindrical bushing 234. The periphery of the latter clears the cylindrical wall of the chamber portion 27 but its outside surface is in contact with the inner ends of the radial plungers 112 as best seen in FIGURE 1. The ring arrangement 116 includes an adjustment sleeve 236 the outer cylindrical surface of which is adapted to rotate within the ring or bushing 234. Two diagonally opposed slots 23% are formed in the sleeve 236 to accommodate the ends of a pin 24%. The ends of the latter are free of the ring 234 and an intermediate portion of the pin is fixed to the shaft 298 to rotate therewith. The pin 24% also extends through an adjustment bushing 24-2 herein described as a hub cam which is located within the sleeve 236 and which is adapted to serve as an eccentric drive member. The adjustment sleeve 236 and the hub cam 242-are adapted to rotate together with the shaft 208 because of the pin 240 but at the same time the sleeve 236 may be moved in the direction of the axis of the shaft 208 because of the slots 238. The diameter D of the hub cam 242 and as indicated in FEGURE 1 is constant along an axis which is at an angle with the axis of the shaft 203 and the bore within the sleeve 236 conforms with the diameter of the hub cam 242 permitting relative sliding motion of the two pieces. FIGURES 1 and 3 show the sleeve 236 at one extreme position (the lowest) to which it may be adjusted anda clearance space 259 between the hub 232 and the hub cam 242 illustrates the extent to which adjustment may be had by 'rneans of the cam plate 202 as will further appear. Surrounding the shaft 268 and immediately above the ring arrangement 116 is a spring retaining plate 252. A coiled spring 254 is retained between this plate and the lower face of the housing portion 22.

Cooperating with each plunger 112, which may be made of nylon, and the corresponding diaphragm 104- is a spring retaining plate 256. Between this plate and the inner wall of the corresponding cover plate 38 is a frustoconical spring 258. This spring insures that the corresponding plunger 112 will be retained in contact with the ring 234 of the ring arrangement 116.

In operation of the pump by means of the eccentric device, it may be assumed that the tongue 216 of the shaft 203 is connected to some portion of an engine to be driven thereby. It is also assumed that the threaded connection 142 will be connected to the engine manifold by a suitable conduit and thereby make it possible to bring the chamber 141) under a vacuum. The chamber 142 on the opposite side of the diaphragm will be subject to the atmosphere by venting through the engine crankformed by longitudinal adjustment of the threaded plug 184. When starting the engine, however, the fuel in the pump discharge will be at 0 pressure and the spring 180 will be extended to its maximum length causing the link 170 to be located at its maximum counterclockwise position around the pin 186 as viewed in FIGURE 2. This in turn will cause the cam plate 202 to so rotate as to raise the ring arrangement 116 with respect to the bushing 242 and increase the strokes of the plungers 112 for maximum pump delivery. As soon as the engine starts, hOW- ever, the fuel pressure acts on the diaphragm 160 to compress the spring 180 and return it to its normal operating length and loading. The cam plate 202 will rotate correspondingly in a clockwise direction as viewed in FIGURE 2 to reduce the eccentricity of the ring arrangement 116 and secure the proper and required pump displacement.

When the engine is operating at idle, the vacuum in the manifold is at a maximum. This increases the load on the pressure regulating spring 180 by causing the diaphragm and rod 148 to move to theleft as viewed in FIGURE 2. This rotates the cam member 202 in a clockwise direction as viewed in FIGURE 2 and decreases the stroke or displacement of the pump plungers.

If the load on the engine changes at any predetermined number of revolutions per minute, the manifold vacuum will increase or decrease and reset the delivery and output pressure of the pump.

Under operating conditions of a high number of revo lutions per minute and no load, the vacuum in the engine manifold is at a maximum thus causing the ring arrangement 116 to move in such a manner along the shaft 208 as to decrease the stroke. If the load changes when the revolutions per minute are constant, the vacuum changes and corrects the pump stroke for that load and speed.

From the above, it is to be noted that the combination of controls provides various fuel pressure characteristics at various speeds or loads which are desirable for the best engine performance. The necessity of a pressure regulating valve and a bypass line for excess fuel is eliminated and only one spring is needed in carrying out the two control aspects. The pump may be said to present a fuel pump output pressure control in which the strength of a pressure biasing spring is modulated by engine manifold vacuum.

Although the eccentric drive device is particularly designed for use with a fuel system in which the fuel is injected under pressure into the combustion chambers of an engine, it is not limited to such use for it is adaptable in connection with an engine carburetor system accompanied by an appropriate change in the rating of the spring 180. In either eventi.e.-whet-her fuel injection or fuel carburetion is used-fuel delivery by the pump 'herein described is effected because of the eccentric drive device as a function of the speed and load of the engine.

We claim:

-1. An eccentric drive device having a housing, a shaft journaled in said housing, a cylindrical hub cam fixed to and surrounding said shaft and having its axis inclined to the axis of said shaft, said hub cam being adapted to serve as an eccentric drive member, a ring arrangement having a cylindrical outer surface with an axis parallel with said shaft, an inner surface ofsaid ring arrangement conforming with said hub cam, and means for moving said ring arrangement along said shaft and hub cam to vary the eccentricity of said ring arrangement.

2. An eccentric drive device having a housing, a shaft journaled in said housing, a hub cam adapted to serve as an eccentric drive member and fixed to and surrounding said shaft and having its axis inclined to the axis of said shaft, a multiple ring arrange-ment having a cylindrical outer surface with an axis parallel with said 1 shaft, an inner surface of said multiple ring arrangement conforming with said hub cam, means holding said hub cam and an inner ring of said multiple ring arrangement in nonrotative relation, a spring mounted in said housing and acting on said ring arrangement in one direction along said shaft, pressure actuated means for moving said ring arrangement along said shaft against said spring, and the arrangement being such that movement of said ring arrangement with respect to said hub cam along said shaft serves to vary the eccentricity of said ring arrangement.

3. An eccentric drive device having a houing, a shaft journaled in said housing, a hub cam fixed to and surrounding said shaft to rotate therewith as an eccentric drive member and having its axis inclined to the axis of said shaft, a multiple ring arrangement having a cylindrical outer surface with an axis parallel with said shaft, an inner surface of said multiple ring arrangement conforming with said hub cam, a cam plate surrounding said shaft and arranged upon rotation about said shaft to urge said ring arrangement in the direction of the axis of said shaft, pressure actuated means for rotating said cam plate to effect said urge and thereby vary the eccentricity of said multiple ring arrangement.

4. An eccentric drive device such as set forth in claim 3, including a spring acting against said multiple ring arrangement and urging the latter toward said cam plate.

5. An eccentric drive device having a housing, a shaft journaled in said housing, a cylindrical hub cam fixed to and surrounding said shaft to rotate therewith as a drive member and having its axis inclined to the axis of said shaft, a multiple ring arrangement with an outer cylindrical surface coaxial with said shaft and an inner cylindrical surface conforming with said hub cam, a first spring mounted in said housing, means acting against said first spring and including pressure actuated means and vacuum actuated means, a cam plate surrounding said shaft and urging said ring arrangement in one direction along said shaft to vary the eccentricity of said ring arrangement with respect to said shaft, a second spring surrounding said shaft and acting in the other direction and against said ring arrangement, and linkages connecting said first spring to said cam plate to serve against said pressure actuated means whereby the action of said first spring may be modified by action of said pressure actuated means and vacuum actuated means.

References Cited in the file of this patent UNITED STATES PATENTS 1,149,728 Ciarlo Aug. 10, 1915 1,191,230 Rich July 18, 1916 1,901,098 Guinness Mar. 4, 1933 2,356,993 Glasner et a1 Aug. 29, 1944 2,539,277 Schroepfer Jan. 23, 1951 2,548,501 Simpson et a1 Apr. 10, 1951 2,765,751 Osius Oct. 9, 1956 2,795,968 Eriksson June 18, 1957 2,900,839 Mackintosh Aug. 25, 1959 FOREIGN PATENTS 802,046 France May 30, 1936 577,287 Great Britain May 13, 1946 1,005,801 Germany Apr. 4, 1957

Claims

1. AN ECCENTRIC DRIVE DEVICE HAVING A HOUSING, A SHAFT JOURNALED IN SAID HOUSING, A CYLINDRICAL HUB CAM FIXED TO AND SURROUNDING SAID SHAFT AND HAVING ITS AXIS INCLINED TO THE AXIS OF SAID SHAFT, SAID HUB CAM BEING ADAPTED TO SERVE AS AN ECCENTRIC DRIVE MEMBER, A RING ARRANGEMENT HAVING A CYLINDRICAL OUTER SURFACE WITH AN AXIS PARALLEL WITH SAID SHAFT, AN INNER SURFACE OF SAID RING ARRANGEMENT CONFORMING WITH SAID HUB CAM, AND MEANS FOR MOVING SAID RING ARRANGEMENT ALONG SAID SHAFT AND HUB CAM TO VARY THE ECCENTRICITY OF SAID RING ARRANGEMENT.