US1747245A - Rotary force-feed piston pump - Google Patents

Description

Feb. 18, 1930. HQ JoHANsoN ETAL 1,747,245

ROTARY. FORCE FEED PIvSVTON PUMI Filed Feb. 12, 1929 2 sheets-#sheet f 1 Pefenteel Feb. 1s, 1930 UNITED STATES PATENT@ ori-ICE `ROTARY FORCE-FEED PISTON PUMP Application led February 12, 1829, Serial No. 339,406, and in Germany January 81, 192,8.

This invention relates to rotary piston force feed lubricating oil pumps with a plurality of pistons whose stroke is separately variable, and having several force feed points and 5 which are especially suitable for use in motor vehicles.

There are already known piston pumps in which the piston, while the pump is in operation, is rotated around its longitudinal axis and while it rotates is at the same time displaced axially against the action ofa spring. lhe axial displacement produces the movements of the piston. The movements of the piston may be determined on the one hand in the known manner whereby at one end of the hollow piston an annular ring face is formed as a cam face which, during the rotation of the piston is following in a curve which is formed to correspond with the length of the stroke. On the other hand, the said curve may also be provided on the annular ring face of the piston by forming this in a plane of section taking an inclined position to the axis, and which for instance may bear on a fixed stud, so that in this manner the move.

ments of thepiston are produced, or else the curve is formed by a corresponding groove which has been formed in position and in which engages a gudgeon pin. In each of the first named instances, a compression spring which is positioned Within the hollow piston is called upon lto press the piston always against its curve in order to produce the movement of the piston, whereas, when the piston is formed with the groove drilled into the same, the spring may be omitted, because in such a case, by reason of the engagement of the gudgeon pin in the groove, the piston is positively guided b eachside of the groove'.

A force feed lubricating oil pump which is constituted in this manner will always deliver an equal quantity of oil. Sometimes it will, however, be necessary to vary the quantity of oil delivered which will prove of especial advantage in those cases in which the piston pump, in the shape of a small oil pump, is designed to serve for the oiling of the cylinders of combustion engines. The variability of the quantity of oil delivered will permit the use of the same size pump for combustion engines of'varying size, seeing that the quantit of the oil delivered may always be adjuste in conformity with the supply of oil required by the cylinders of the combustion engines, so that an excessive oil supply is definitely avoided which will, of course, result in a very economical oil consumption.

` Pumps of the usual type now known tothe art possess as a rule, only one or at the most two force feed points. In the main, however, we only find that type of pump in which one suction point and one force point are crowded into a narrow space, in a convenient place of the engines, asfor instance in motor cycle engines.

At the present stage of engineering and of the construction of combustion engines, and especially of those which are designed to serve for use in motor cycles, the provision of only one force feed point for supplying the oil in the cylinder of a combustion engine will not, as a rule., be suliicient, for there are several other places in a motor vehicle which require lubrication, as for instance, the chain, or the faces of the cams in motor vehicles with upper valve motion. With the present form of pump having one force feed point only, one or more pipes of suitable diameter are branched ofi for thepurpose of supplying the above mentioned oil consuming places with oil, which is after all only an emergency arrangement, because Whenever one' has to deal with a total oilsupply which is of some importance, this arrangement will prove to be unable to supply all the oil consuming places with that quantity of oil which thev absolutely require and it will thus happen that one or the other of these oil consuming-places will be supplied with oil inadequately.

Therefore, we have designed rotary piston pumps with several force feed points which are all subject to the action of the moving l piston by providing for instance the piston at both ends with suitable slots or grooves which are drilled into the same and which produce the action of suction and of forcing and by connecting these openings in the pis'- ton to suitable tubes supplying the oil to the various places of oil consumption. At' the same time the one, two or even more pistons are guided, with regard to their longitudinal movement, with positive motion and we have provided the same with a throw controlling device which is fit and adapted while the pump is in operation, or at rest, to vary the length of stroke of the pistons and to obtain thereby a faultless adjustment of the throw and eliminate the usual inconveniences, so that the quantity of oil which is being delivered may be so adjusted that it is each time coping with the quantity of oil which is actually required, and which will remain always the same during the whole time the throw controlling device is set and adjusted to that particular quantity of the supply.

' A particular advantage and an additional characteristic of the present invention lies in the location of several pistons in one and the same axial direction ofthe same. The pistons are connected by suitably designed coupling means with the driving piston, so that only one driving spindle is needed for moving the totality of the pistons. The adequately designed and constructed coupling means has for its object to accomplish any desired variations of the throw, regardless of the coupling together of the pistons, o that the varying of the throw' of one of the iistons will not interferezin any way with the other pistons. In this manner there is provided a rotary piston umpl which, with a minimum expenditure ot) material and the smallest admissible numberof component parts, makes use of only one drive and one suction point, and supplies simultaneously two, three or more oil consuming places withl oil, and the whole assembly may be made of such small dimensions that when fitted to 'a motor cycle engine or the like, the accessibility of the engine is not impaired.

The invention is illustrated in Figs. 1 to 10 of the accompanying drawing, and in which Fig. 1 is a front elevation, Figs. 2 and 4 each show a longitudinal view through the pump with the pistons in different positions, while Fig. 3 is a cross sectional view of the pump about the line A-B of Fig. 2 and Fig. 5 is a cross sectional view of the pump about the line C-D of Fig. 4. Figs. 6-10 are showing various positions at which the throw controlling device has been set within the grooves which are formed in the pistons.

In the embodiment of our invention, which is shown in the drawing, a rotary pump with three force points and one throw controller device for each piston, has been adopted.

is putting in rotation two or three pistons by means of an endless screw and worm gear. 'Ihe bearings of the pistons are closed by screws 5 and the interposing of a packing 6, so that the pistons on the one hand are prevented from falling out and on the other hand the escape of any oil is prevented. The

there is formed in the iston 3 a slantin anl nular groove 9, in which engages the t row controlling device which imparts to the piston a positive motion. The piston 3 has the function of sucking the oil which is flowing from a point of use and passing it to the suction port 10, disposed at the rear of the two pistons (shown by dotted lines in Figs. 2 and 4 and .clearly illustrated in Fi 3) through the boring 11 on the Vpiston beine' suitably displaced longitudinally towards the right, and on rotating the piston to a still greater extent to force the same through the tube 12 into the inspection chamber. From here the oil is again sucked by the groove 7, provided on the other end of the piston, and isforced into the boring 14, which communicates with the force point 15, which is located directly opposite the suction port 10. In this manner the force feed point 15 may be controlled throughthe inspection chamber.

The piston 4 is supplyin the force point' 16 with oil, in such a way t at the oil passes from the boring 11 into a longitudinally extending boring 18. By the boring 18 and the groove 19 on the rlght hand end of the piston 4, the oil is sucked in conformity with the throw of the piston and is delivered to the force point'16.

As a third piston there is provided in the casing 1, the piston 20 which, however, is not moved directly by the driving spindle 2 but by the piston 4, the piston 4 having on thev left hand end a transversely extendin groove 21, in which enga es a spring 22 whic is provided on the rig t hand end of the piston 20. In this manner the piston20 is coupled with the piston 4 and accomplishes the same rotary motion as the piston 4 itself.

The left end of the piston 20 presents the distinctive feature of that pump in the form of a groove 23, so that the piston 20, in performing the appropriate motions (rotation and displacement) willsuck the oil by the boring 24 which communicates with the analogous -longitudinal boring 17 which is disposed in front of the piston and forces the oil into the place of consumption 25. The pistons 4 and 2O are likewise provided with slanting annular grooves 26 and 27 with which engage the controlling devices by t which on the one hand the pistons are guided In the pump casing 1 a driving spindle 2 with positive motion. in their longitudinal movements and on the other hand are causing the variations in the length of their stroke. The two pistons are coupled in such a manner with each other that the slanting annular grooves 26 and 27 expand parallel 1n respect to one another and the positive motion and the longitudinal displacement of the two pistons incidental thereto, (by reason of the position of the slanting grooves) are accomplished always in the same direction and thus the do not work in opposition to each other. he guide ofthe slot and key in the coupling need thus only be of the length of the stroke of the coupled pistons, because the variation in the length. of the stroke may on the one hand be of such an amount as the available total length of the stroke of istons (if the curve 1s being varied in suc a way that the pump is not delivering any oil the variation of the curve corresponds to the total length of the stroke) whereby it is obtained that the total length of the two pistons 4 and 20 which are coupled' with each other will not be excessive. The characterist-i of the pump described heretofore are shown in Fig. 2 and present the position of the pistons after having completed the suction and forcing motions with the pump Kworking at full capacity in all force points.

In F ig- 4 the corresponding parts of the .Y pump are designated with like reference numerals, but the positions are dierent from those shown in Fig. 2 which is due partly to the turning movement of half a revolution given to the. pistons and partly to the change 1n the position of the controlling device (variation in the length of the stroke). The change in the position of the stroke or throw controlling device is represented in Figs. 1 and 5.

On the frontal side of the pump casing are fitted in convenient places for each piston (3, 4 and 20) pointers 28, 29 and 30, each of them being arranged on dials 31, 32 and 33, which enables the operator to read oli readily from the scale the variations in the position of the pistons. The pointer 28 indicates the full capacity of the piston 3, while the pointer 29 indicates half the full capacity, and the pointer 30 only about one fourth part of the full capacity of the pistons 4 and 20 respec tively. The controlling device .by itself consists in its internal construction of a stud 34 which being formed with various steps is conveniently seated in the casingl and which is provided on one end with the pointer and on the other end with two'zeurves 35 and 36 which. in the annular grooves (9, 26 and27) o epistons (3,4and20). Thesaid curves are shaped to orm ellipses and they are positioned with their axes at right angles to each other. manner there is 1mparted to the istons the itive motion above mentione with regar to their longitudinal movements and the rotation of the curves permits the variation of the stroke, through which however, the positive motion is not impaired. (This is described still more in detail hereinafter.) -The rotated curves are shown in Fig. 5 in the lower controlling device and are clearly illustrated. The studs 34 of the throw controlling device will the stud 34 allow rotation by means of the pointer carried by the stud and thus the variation of the length of the stroke. Y

In Fig. 4 is shown in the main, apart from' the other component parts ofthe pump already mentioned, the change in the position of the two coupled pistons 4 and 20 relative to each other, this change corresponding to the variation of the throw represented in Figs. 1 and 5. From Fig. 4 it is plainly seen that the guiding of the coupling in the space '39 is still ample, even in the case of a very large variation of the throw, in order to ensure a faultless transmission of the moment of torsion from the piston 4 to the piston 20, while however, the length of the two pistons couled with-each other isV such that the total ength of the pumpremains a reasonable one. It is at once evldent that the piston 3 by providing similar coupling means, be able to accomplish thetransmission of the moment of torsion to a fourth piston, so that in this manner a fourth force point may be created. By suitable construction of the piston additional pistons may be axially connected up by means of coup of the kind such as have just been descri all of which, however, can be supplied with oil from one suction point only, and all the pistons can be driven by one and the same spindle (spindle 2).

Now, hereinafter is described the special part which characterizes the pump, viz., the throw controlling device with its function and action. The grooves which are formed on the pistons 2, 4 and 20 are formed and arranged in such a way that the groove 40 is drilled in a vertical position with respect to the axis of the piston, while'the groove 41 is extending in a slantiug position with respect to the The ve 40 is narrower and deeper 'than Ythe groove 41 and the difference between the width of the twoV grooves represents the length of the throw. The walls of the opposite points of t eir ath with the walls of the groove 41. vThus t e groove 41 consti- -I tutes the throw curve groove. With theseV grooves 40 and 41 and 41 engage the suitably formed curves (ellipses) and 36 and dis d on the throw controlling member an which are positioned crosswise to each other, so that the short axis of the ellipf-e axis f the `ellipse oove meet attwoV to the width of groove 40. Whenever the throw controlling member 34 with the curves 35 and 36 is placed in such a position that the large axis of the ellipse 35 is engaging in its entire length with the walls of the groove 41, the complete stroke of the piston will be accomplished by reason of the positive action of the grooves. The short ellipse 36 engages in the groove 40 (the spacing of the ellipse corresponds to the depth of the grooves) but same does not exert any effect because the location and position of the grooves and the ellipse are such that they cannot counteract or act in opposition to the normal throw of the piston. L

The maximum quantity which can-be delivered by the pump will be attained by the position of the curves (ellipses) 35 and 36 which they take between the grooves 40 and 41 as is shown in Figs. 6, 7 and 8. As already explained the curve 35, inasmuch as the large axis of the same is in its entire length in engagement with the groove 41, will provide a complete throw of the piston. How this can be achieved is shown in Figs. 6, 7 and 8. After having secured member 34 of the throw controlling device both against axial displacement and against rotation, the pistons are compelled, according to the degree of inclination of groove 41 and of the compulsory guiding means of the curve 35,

to take advantage of the difference between the inclined position of the walls of the groove 41 and the fixed guiding means 35 for insurin the throw.

In Fig. 6 the piston is shown in its posi-"- of groove 40 are in contact at the left against the'left hand narrow side of the curve 36. In Fig. 7 the piston is shown in its position when displaced completely towards the left when the compressing of the walls of the groove towards the curves takes place in the reverse order to what has been explained above. In Fig. 8 is shown the displacement of the piston in an intermediate position and consequently also the intermediate position of the curve 36 within .the groove 40. The short axis of the` curve 36 therefore corresponds tothe length of the stroke and groove 40 is twice as wide as the short axis of the ellipse 36. In conformance with the displacement of throw of the piston, the large axis of the ellipse of curve 35 must be three times as long as the short axis of the curve 36.

In Fig. 9 is shown a slight rotation of the throw controlling member 34. By reason of this rotation it is no longer possible for the complete throw to be accomplished. In this figure is distinctly shown the space 42 which is being created between the .curve 35 and the wall of the groove 41. This space corresponds to the diminution of the throw. If

4the groove 41 will contact with the right hand side of the curve 35, while the left hand wall of the groove 41 will diverge from the curve 35. On the other hand, however,

the left hand wall of groove 40 is in contact with the left hand side of curve 36, and the right hand wall of the groove is free and presents the space 43. In rotating the piston through 180 the compression is changed in reverse order. While when the throw controlling member is set in a normal position a fitting or bearing of the wall of the groove 41 takes place only against the curve 35 the -fitting of the curves 35 and 36 with the walls ofh the grooves 40 and 41 will change on rotating the throw controlling member which of course, is tantamount to a compulsory guiding also during the variation of the stroke by means of the throw controlling member. The variation of the throw and the diminutionof the quantity of oil delivered which is ensuing therefrom, will always'be alike by reason of the compulsory motion and thus the places of consumption are supplied always with the same quantity of oil and that which is needed to warrant efficient oiling.

In case the piston 20 for instance should not be needed for oiling, its throw may be completely discarded on rotating the throw controlling member from its full capacity position through an angle of 90 as is shown in Fig. 10. The whole longitudinal axis of the ellipse 36 will spring in its entirety into the groove 40 while the fitting of the curve 35 with the walls of the groove 41 will cease.

The piston receives the compulsory motion only through the groove 40 extending vertically to the axis of the piston and therefore the piston remains axially un-displaced although still revolving round Aits axis.

A pump embodying this invention offers considerable advantages over those of existing types in that it is extremely compact, there are only a small number-.of simple moving parts, all of which are easy to manufacv ture, and therefore the utmost reliability is assured.

Variations in the details, when manufacturing the pump, will not influence the claims hereinafter set forth, nor will one thereby depart from the spirit and scope of our present invention.

We claim 1. In a rotary piston pump, a driving member, a primary piston actuated from said driving member, and secondary pistons actuated for said primary piston, and means for varying the stroke of each piston separately.

2. In a rotary piston pump, a driving member, a primary piston actuated from said driving member, secondary pistons actuated from said primary piston, slotand key coupling means between said primary and secondary pistons, and means for varying the stroke of each piston separately.

3. Ina rotary piston pump, a driving member, a primary piston actuated from said driving member, secondary pistons vactuated from said primary piston, slot and key 'coupling means between said primary andsec ondary pistons, means Jfor varying the stroke of each piston separately, said means comprising grooves in each of said primary or secondary pistons, formed respectively at l right angles and obliquely to the axis of the respective piston, and adjustable studs engaging therewith.

4. In a rotary piston pump a driving member, a primary piston actuated from said driving member, secondary pistons actuated from said primary piston, slot and key coupling means between said primary and secondary pistons, means for varying the stroke of each piston separately, said\means comprising grooves in each of said primary or secondary pistons, formed respectively at right angles and obliquely to the axis of the respective pistons, and adjustable studs engaging therewith, said studs being formed with elliptical bearing surfaces arranged at right angles to each other, and adapted to engage respectively in lsaid aforementioned grooves. c

HERMANN J OI-IANSON. GEORG KPPEL.

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