US2528764A - Reversible flow rotary pump - Google Patents

Description

Nov. 7, 1950 J. T. LEONARD REVERSIBLE FLOW ROTARY PUMP 3 Shets-Sheet 1 AFiled. April 6, 1946 Nov. 7, 1950 J. T. LEONARD 2,528,764

REVERSIBLE FLOW ROTARY PUMP Filed April 6, 1946 3 Sheets-Sheet 2 Nov. 7, 1950 J. T. LEONARD I 2,528,754

REVERSIBLE FLOW ROTARY PUMP Filed April 6, 1946 3 Sheets-Sheet 3 Patented Nov. 7, 1950 UNITED STATES PATENT oEElcE REVERSIBLE FLOW ROTARY PUMP John T. Leonard, Evanston, Ill.

Application April 6, 1946, Serial No. 660,055

8 Claims.

My invention relates generally to pumps, and more particularly to rotary pumps in which the direction of iiow of the liquid may readily be reversed.

In some uses of liquid pumping apparatus, it is desirable to pump the liquid into one conduit until the pressure therein attains a predetermined value, and then to vent such conduit and supply the liquid under pressure to a second conduit. For example, in lubricating systems of the so called dual progressive type, each of a plurality of bearings is supplied with a measuring valve or feeder. These measuring valves are connected in series by suitable piping, and lubricant under pressure is alternately supplied to opposite ends of the piping. This is ordinarily accomplished by alternately connecting' a conventional pump to the opposite ends of the conduit system, or by providing a four-way valve effectively to reverse the connections between the pump and the ends of the conduit,

In accordance with the principles of my invention, the necessity of using a reversing valve or of using detachable couplings for connecting the pump to the conduit system is avoided, since the pump itself is effective to pump in either direction, that is, into either end of the conduit system, while relieving lubricant pressure at the other end of the conduit. Y

It is therefore a fundamental object Aof my invention to provide an improved reversing rotary pump.

A further object is to provide an improved reversing pump in which the direction of pumping action is reversed when the pressure at the outlet of the pump attains a predetermined maX- imum value.

A further object is to provide an improved rotary pump in which the direction of flow may be readily reversed.

A further object is to provide an improved means for indicating the operating condition of the pump and of the lubricating system with which it is used. Y

A further object is to provide an improved pump especially adapted for dual progressive 1ubricating systems, which is simple and compact, and may be economically manufactured.

Other objects will appear from the following description, reference being had to the accompanying drawings, in which:

Fig. 1 is a central vertical sectional view;

Y Fig. 2 is a sectional View taken on the line 2 2 rof Fig. 1;

Fig- 3 is a fragmentary sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary sectional view taken on the line 4--4 of Fig. 2;

Figs. 5 and 6 are fragmentary sectional views taken on the lines 5-5 and 6 6, respectively, of Fig. 1;

Fig. 7 is a fragmentary sectional view taken on the plane of the line 2--2 of Fig. l, and showing the eccentric in the position opposite to which it is shown in Fig. 2;

Fig. 8 is a detail view showing the straps employed to hold theplungers in contact with the eccentric; and

Fig. 9 is a sectional, partly diagrammatic, view of a lubricating apparatus with which the pump is designed to be used.

Referring particularly to Figs.` l and 2, the pump comprises a body casting I0 having a bore I2 formed therein. The bore I2 is cylindrical except for the provision of crescent shaped grooves I4 and I5, which are milled in the casting in line with passageways I6 and I8. Within the bore I2 is a rotor 2li, one end of which is provided with a key slot 22 for the reception of a key 24 formed at the end of a drive shaft 26; The drive shaft 26 has a suitable bearing in a cap 2l closing one end of the bore I2, and is sealed by a packing gland 29.

The rotor 20 has a bore 28 formed therein, one end of this bore being closed by a plate 30 held in place by a split ring spring 32 which ts in a groove 34. The rotor 20 is provided with four pump cylinders 36, in which plungers 33 are reciprocable. Each of the plungers has a head 4I) which engages a hardened steel roll 42 which rotates on a stem 44 located eccentrically of the rotor 20.

The stem M is preferably formed integrally with a block 46 which is pinned to a plunger 48, the plunger being capable of limited longitudinal movement in aligned bores 5G and 5 I. The block 46 has a pair of notches 52, 53, which are adapted to be engaged by the wedge-Shaped end of a detent pin 54. The pin 54 is slidably mounted in an end cap 56 which serves as a closure for the end of the bore I2, and is held in one or the other of the notches 52, 53, by a relatively strong compressed coil spring 5B. The degree of compression of the spring 5B may be adjusted by a plug 60 Iwhich is threaded in the end of the bore 62. The bore 52 has its outer end sealed by `a, plug 64.

The plate 30 is provided with a horizontal groove 66 and an intersecting vertical groove 68. A retainer clip 61 is slidable in the groove 66,

while a similar retainer clip 69 is guided in the vertical groove E8. The ends of the clips 61 and 60 are flanged over the heads 40 of the plungers 38 and thus hold the heads of the latter in engagement with the roll 42.

One end of an L-shaped passageway l communicates with the passageway l0 while its other end is in alignment with the row of cylinders 36. A vent port 'I2 is provided in the upper part of the body casting 0, this port also being in alignment with the cylinders 36.

As best shown in Fig. 6, the lower end of bore is connected by a passage-way 14 to the passageway l0, while as shown in Fig. 5, the upper end of bore 50 is connected by a passageway 16 with the passageway I8. The upper end of bore 50 is closed by a plug '58, while Ythe lower -end' of bore 5| is closed by a plug 19.

A lubricant reservoir 80 is secured to the top of the casting l0 by cap screws 82, a suitable gasket 84 being provided to seal the joint.

The upper ends of passageways |6 and I8 terminate in check valve lchambers 86 and 88, respectively. Each of these chambers is provided with a check valve seat bushing 90 vand a valve retaining spider 92. Ball check valves 0.0 and 98 are located in chamber 85 and 38 respectively.

Assuming that the plunger 48 is in its lower position as shown in Fig. l, and that the rotor is being drivenV counterclockwise as indicated by the arrow in Fig. 2, the lubricant will ow in the direction indicated by the arrows and will be discharged through outlet itting |00 which communicates with passageway i8. A similar outlet tting |02 communicates with passageway |18.

When the pressure in passageway |B exceeds a predetermined value, it acts upon theY lower end vof plunger 40, overcoming the force applied by the spring pressed detent pin 54. lThe upward movement of the plunger 48 is limited by the tip on the plug i8, and when in this position the detent pin 54 engages in the notch 53. The eccentric roller 42 will thus have its pivotal axis shifted above the axis of the rotor 20 and the piston plungers 38 will thus be oscillated through cycles displaced in phase 180 from their former cycles. As a result, the direction of the ow of lubricant caused by the pump will be reversed, so that the flow will take place in directions opposite to those shownY by the arrows in Fig. 2. The resultant pressure in the passageway I8 will cause the check valve in chamber 88 to seat, while the check valve in chamber B6 will open due to the drop in pressure in the passageway i6.

Subsequently, when the pressure in passageway |8 increases to a predetermined value, this pressure will be exerted upon the upper end of the plunger 48 and return the latter to the position in which it is shown in Figs. l and 2, whereupon the eccentric roller 42 will be in such position as to cause the piston plungers to pump lubricant from the passageway I3 to the passageway I6, as indicated by the arrows in Fig. 2.

Thus, lwhile the rotor 20 rotates continuously in one direction, the direction in which the lubricant is pumped is automatically reversed whenever the discharge pressure exceeds Aa, predetermined value.

As best shown in Fig. 9, the ttings |00, |02 are formed t0 provide seats for ball valves |04 and |05, these valves being held adjacent their seats by spiders |00. The fittings |00, |02, are T fittings, the tting |02 having a conduit |00 connected thereto leading to one end of a lubricant measuring or feeder valve ||0. 'I'he other end of the feeder valve ||0 isconnected by conduit |00 to the other T fitting |00.

The feeder valve ||0 may be of any well known construction, such as shown in my prior Patent No. 2,115,637, and has a pair of outlets connected by conduits |2 and 3 to bearings ||4 and l5 which are to be lubricated. The feeder valve |0 is representative of any reasonable number of similar valves which may be connected in series for the lubrication of the bearings on a single machine or on a group of machines.

The feeder valve I0 comprises a body i 6 having a cylindrical bore H8 relieved near its ends by by-passes |20 and |2l. These by-passes are controlled by valves |22 and 23, the valves being Vpreferably secured to a connecting tube |24, the

latter having a central port 26. A charge measuring piston |20 is freely' slidable on the tube |24. This piston has its end faces relieved along their peripheral edges so as to permit complete discharge of measuredrcharges of lubricant through the discharge ports |30 and |.3l`which lead to the conduits 'I I2 and |13, respectively. The valve members |22 and |23 are provided with seats for ball check valves |32 and |33.

Thus when the v'pump is operating to force lu# bricant under pressure'through the T tting |02, the lubricant iiows past the check valve |05, through the conduit |08, rand into the right-hand end of the feeder valve body |15, thereupon forcingA the check valve |32 against its seat. The pressure building up at the right-hand end of the body H0 forces the valve members |22, |23, and their connecting tube Y|24`to the left, the valve |22 thereby uncovering the byepass |20 and permitting ow of lubricant into the space surrounding the tube. |24. Lubricant pressure is thus exerted upon the right-hand end face of the 'hollow piston |28, and forces the latter to theleft. As the piston |28 moves to the left, the lubricant contained in the. space to the left of it is forced through" the outlet |3| andfconduit H3 to the bearing I5. As the piston |28 approaches the end of its leftward stroke, it uncovers the port |26 in the tubev |24, permitting lubricant to iiow into this tube, past the check valve |33, through the conduit |29 to the next feeder valve of the series, and eventually, to the fitting |00.

Upon reversal of the direction in which the lubricant is pumped, the valve members |22, |23, together with tube |24 and piston 28, are moved to the right in a manner similar to that previously described, and the lubricant stored in the bore ||8 around the tube |24 Vis discharged through port |30 and conduit ||2 to the bearing ||4. Upon completion of this discharge stroke, the port |26 is uncovered by piston 28 and lubricant may ow past thev check valve |32 into the conduit |08 and hence through .any other feeder valves connected in this conduit, the lubricant pressure. eventually being applied to the fitting |02.

It is desirable, in the use of lubricating sys-V tems of the character described, that there be provided an indicator to show when a lubricating operation has been completed, and that all'of the feeder valves have operated. One form' of such indicator is disclosed in Fig. 9 as comprising a body |40 having a valve bore |42 formed therein. 'Ihe ends of the bore |42 are suitably connected as by conduits |44 and |46 with. the f1ttings |00, and |02, respectively.A Avalve member |50 is freely reciprocable in the bore- |42, the stroke thereof being limited by bushings V|52 threaded in the ends ef the body |40. Thepisten 5 valve |50 is provided with annular grooves |56, |51, which are in communication with the adjacent ends of the bore |42 through axially drilled passageways |58 and |59, respectively. The piston valve |50 also has a central annular groove |60 which, during the course of the travel of the piston valve |50, is adapted for a brief interval reduced diameter upper end portion |80 of the plunger |16 is guided in a cap |82, and is adapted to be projected therefrom, as indicated by the dotted lines in Fig. 9, when lubricant under sufficiently high pressure is supplied to the bushing |12.

It will be recalled that upon commencement of an operating cycle, lubricant under pressure is initially supplied to the fitting |82. In addition to applying this lubricant pressure to the lubricanting feeder valve H0, this pressure is also transmitted through the conduit |56 to the righthand end of the bore |52, thereby forcing the piston valve |50 to the left to the position in which it is shown in Fig. 9.

After completion of the operation of the series of feeder valves, lubricant under pressure will also be supplied to the fitting 00, and this lubricant may flow through the conduit |44 into the left-hand end of the bore |42 and thence through the passageway |58, annular groove |56, and pas- 1.

sageways |53 and |10, to the bushing |12, the lubricant pressure being applied to the end of the plunger |16 and forcing the latter upwardly until, by projection of its end |80 above the cap |82, it provides an indication that the lubricating operation has been completed.

When the pressure in the return line |09 and return fitting is suicient to operate the indicator, it will also operate the iiow direction reversing mechanism of the pump, by exerting pressure upon the plunger 4B. As the direction in which the lubricant is pumped is reversed, suction is applied by the pump to the tting |62, thereby drawing the ball check valve |05 to its seat. This valve is permitted to move a suicient distance from its seat that a certain amount of lubricant will be drawn into the inlet of the pump before the valve |05 seats, and this lubricant will be drawn from the right-hand end of the bore |42 permitting the piston valve |55 to be forced to the right by the pressure still retained in the fitting |06. As the piston valve |50 moves past its central position, the groove |60 connects passageway |62 to the port |64, and the spring pressed plunger |16 moves downwardly, discharging the lubricant from its cylinder through the ven't passage |62, groove |60, port |54. and conduit |66, to the lubricant reservoir. The piston valve |50 continues moving to the right until arrested by the bushing |52, in which position the groove |51 will be in alignment'with the lower end of the passageway |69, and thus be in a position to conduct lubricant under pressure from the right-hand end of the bore |42 to the bushing |12 upon completion of the next half cycle of operation, to enable the pressure indicator |14 to indicate the completion of the second half cycle.

The pump and indicator `may also be used with centralized lubricating systems of the dual line type, such las that disclosed in Whitted Patent No. 2,260,497, in which the feed valves are connected in parallel between the two conduits leading from the pump. In such systems when lubricant is applied to one of the conduits, the feeder valves operate to supply measured charges of lubricant to associated bearings, and there is no flow of lubricant from the conduit in which the lubricant is under pressure, to the other conduit, but instead, the feeder valves which are connected in parallel between the conduits after operation block the flow of lubricant fromthe conduit in which the lubricant is under pressure, so that the pressure in the latter builds up to a value sufficiently high to cause reversal of the direction in which the lubricant is pumped by the pumping mechanism. When the pressure thus increases, it attains a value suicient to operate the pressure indicator |14, but in such systems the piston valve |59 is so constructed that when moved to the left, for example, the right-hand end of the bore |42 is placed in communication with the passageway |59, so that as the pressure in the fittingv |02 builds up, the piston valve will be moved to a position in which the pressure in the fitting |02 may be applied to the plunger |12 of the pressure indicating device |14. The piston valve may be of substantially the same construction as shown in Fig. 9, except that the grooves |58 and |51 will be spaced closer to the ends of the piston valve. For example, the groove |51 would be located so that with the piston valve in the position in which it is shown in Fig. 9, it will be in alignment with the'lower end of the passageway |69, and since the groove |58 will be correspondingly displaced, it will not be in alignment with the lower end of passageway |68.

From the foregoing, it will appear that when the pump is continuously driven and is connected to feeder valves, such as ||0, connected in series, or to a group of feeder valves of the type which are connected in parallel, the pump will operate alternately to supply lubricant under pressure to the outlet conduits, such as the conduits |08, |09, which are connected to the feeder valves. After the series of feeder valves have been operated, each to supply measured charges of lubricant to its associated bearings, the pressure in the discharge line of the pump builds up sufficiently to move the plunger 48, and thereby cause reversal of the pump inlet and discharge, as previously described.

The drive shaft 26 of the pump may be connected directly to a moving part of the machine, the bearings of which are being lubricated, or may be driven by an electric motor preferably connected so as to be energized whenever the machine being lubricated is in operation. In other installations, the pump may be arranged to be driven at timed intervals through the use of a suitable timing mechanism which energizes the pump driving motor at certain intervals, for example, during ten minutes of each hour while the machine being lubricated is in operation.

Irrespective of the manner in which the pump is driven, it will be clear that while it is operating, it willy alternately supply lubricant under pressure to the two conduits, as conduits |08,

[09,-the alternation being effected whenever the pressure in the discharge conduit builds up to a valve sufficient to move the plunger 48 in opposition to the force tending to hold it in one position, which is applied by the spring 58 through the detent plunger 54.

The pump is of a simple'construction, and by removal of the end caps 21 and 56, the working parts of the pump are accessible for servicing or replacement.

While I have shown and described a preferred embodiment of my invention, it will be apparent that numerous variations and modiiications thereof may be made without departing from the underlying principles of the invention. I

therefore desire, by the following claims, to

include within the scope of the invention, all such variations and-modications by which substantially the results of my invention may be obtained through the use of substantially the same'or equivalent means. Y y l I claim: 1.`A pump for centralized lubricating system comprising a body having two passageways, a

lubricant reservoir, ports connecting the reservoir to the passageways, check valves cooperable with the ports to permit iiow of lubricant from the reservoir to the passageways and to prevent lubricant flow in the reverse direction, two'outlet ports for said passageways respectively, check valves cooperable with the outlet ports to permit flow of lubricant from the passageways but preventing ow in the reverse direction, means within the pump body to pump lubricant from either passageway to the other, and means to reverse the eiective pumping action of said last named means whenever the pressure inrone of the passageways exceeds the pressure in the other passageway by a predetermined amount.

2. In a pump capable of pumping a fluid in either direction between two passageways, the combination of a cylindrical bore having ports at diametrically opposite sides and communicating with the passageways respectively, a member rotatable in said cylindrical bore, said member having a plurality of pairs of cylinders formed therein, a plurality of plungers one reciprocable in each of said cylinders, an eccentric member engaging the ends of said pistons and operable to reciprocate them in their cylinders as said member rotates, fluid pressure operated means for changing the direction of eccentricity of said eccentric means thereby effectively toY reverse the direction of pumping action of the pistons, and means to rotate said member, and means connecting the passageways respectively to the fluid pressure operated means, whereby the relative pressures of the fluid in said passageways determines the direction in which the fluid is pumped.

3. In a pumping mechanism, a body having a bore extending therethrough, a rotor mounted for rotation in the bore, said rotor having a plurality of radially extending cylinders formed therein, headed plungers respectively reciprocable in said cylinders, a normally stationary cylindrical means eccentric of the axis of the rotor, means engaging the heads of said plungers to hold them in rotary sliding engagement with said normally stationary means, means provid-v ing a source of the liquid to be pumped, and passageways inthe body extending from the source.

to opposed substantially semi-circumferential portions of the Vouter surface of the rotor in alignment with thecylinders formed therein.

4. A rotary reversible low lubricant pump comprising a body provided with a pair of inlet passageways, means connecting said inlet pas# sageways to a source of lubricant, a check valve in each of said passageways operable to close thepassageway when the lubricant therein tends to` flow toward the reservoir, a rotor in said pump body, said rotor having a plurality of cylinders formed therein, the outer ends of each of said cylinders being in communication with each of said passageways during slightly less than onehalf of a revolution of the rotor, plungers re. ciprocable in said cylinders, a normally station-- ary member engageable by said plungers and located eccentrically with respect to the axis of rotation of the motor, means for holding said plungers in engagement Vwith said member,` lubricant pressure operated means forchanging the eccentricity of the member through an angle of substantially said last' named means being operable when the discharge pressure inV one of said passagew-ays exceeds a predetermined value, and detent means to hold said lubricant pressure operated means in position until the pressure in the other of said passageways attains said predetermined value.

5. kThe combination set forth in claim 4, in which the means for holding the plungers in engagement with the member comprises a pair ofrelatively movable straps each embracing oppo site plungers.

6. The combination set forth in claim l, in which the means for reversing Vthe pumping action comprises a cylinder having its ends connected respectively to said passageways, a` plunger reciprocable in the cylinder, and in which the pumping means includes an element the direction of eccentricity of which may be varied by movement of the plunger;

'7. The combination set forth in claim 3, in which means are provided to move the normally stationary eccentric means in one direction or Vthe other along a diameter of the rotor ink response to substantial differences in the liquid pressure in the passageways. y

8. The combination set forth in claim. 3, inv which means are provided to move the normally stationary eccentric means in one direction or the other along a diameter of the rotor in response to substantial` differences in the liquid pressure in the passageways, and in which arelatively powerful detent means is provided to hold the eccentric means stationary;

JOHN T. LEONARD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,950,158 Barks Mar. 6, 1934 2,277,991 Leonard Mar. 31, 1942 FOREIGN PATENTS Number Country Date 596,262 France Aug. 4, 1925V

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