US3703078A

US3703078A - Rapid response fluid drive

Info

Publication number: US3703078A
Application number: US134949A
Authority: US
Inventors: Richard M Nelden; Thomas J Ryan
Original assignee: American Standard Inc
Current assignee: AMERICAN DAVIDSON Inc A CORP OF MICH
Priority date: 1971-04-19
Filing date: 1971-04-19
Publication date: 1972-11-21
Anticipated expiration: 1989-11-21

Abstract

A fluid coupling equipped with means for admitting liquid to the work chamber at a variable rate for effecting quick output speed changes. The admitting means includes a rotating reservoir containing a reserve ring of liquid, and a scoop tube movable into the reservoir to extract liquid from the ring at a variable rate in accordance with the scoop tube position, and the replenishment rate for the reservoir.

Description

United States Patent Nelden et al. 1 Nov. 21, 1972 [s41 RAPID RESPONSE FLUID DRIVE 2,989,851 6/l96l Sinclair ..60/54 3 320,748 5/1967 Nelden ..60/54 [72] Inventors. Richard M. Nelden, Southfield,

Thomas Ryan, Detroit both of 3,403,514 l0/l968 James ..60/54 Mich. Primary Examiner-Edgar W. Geoghegan [73] Assrgnee: American Standard Inc., New York, Atmmey ]0hn McRae, Tennes I. Irstad and Robert G. Crooks [22] Filed: April 19, 1971 I [57] ABSTRACT [2]] App]. No.: 134,949

A fluid coupling equipped with means for admitting liquid to the work chamber at a variable rate for ef- [52] U.S.Cl..' fecfing quick outputspeed changes The admitting [51] Int. Cl 60/54 means includes a rotating reservoir containing a [58.] Field of Searc reserw ring of liquid and a scoop tube movable into References Cited the reservoir to extract liquid from the ring at a varia- UNITED STATES PATENTS ble rate in accordance with the scoop tube position,

and the replenishment rate for the reservoir.

2,299,049 10/ 1942 Ziebolz ..60/54 9 Claims, 1 Drawing Figure I3 83 U 78 H 7 5 4645 52 E r 1 5 5'6 54 I, 3: l i 55 I 44 y g 7 C 72 22 2a s9 63 i 5 a I 25 23 9 3:15:3 6 2 a i g 34 9 41 7 a 2O 55 4 7 2/ g 23 q as /a 71 1512 32. i 66 I 46 48 6 50 5 PATENTEDNUVZI 1912 3,703,07

GLEZR INVENTORS RICHARD M. NELDEN THOMAS J. RYAN RAPID RESPONSE FLUID DRIVE SUMMARY This invention presents a variable speed fluid coupling having an improved response time for achieving speed increase or decrease. The design permits a material reduction in the amount of working fluid in circulation over that required in a conventional design to meet extremely fast response time requirements.

In the present invention a quicker speed response time is attained by varying both the rate of removing fluid from the work chamber and the rate of filling the work chamber. The preferred arrangement includes a rotating reservoir and a liquid transfer or fill tube dipping into a liquid ring within the reservoir. The ring is continuously replenished by liquid from an external pump; at constant speed the fill tube skims a normal amount of liquid frqgn the ring and transfers it to the work chamber. By causing the fill tube to penetrate more deeply into the liquid ring the fill rate is immediately increased because the tube is then handling both the normal circulation flow and the reserve supply provided by the reservoir fluid. By causing inlet transfer tube to move out of the liquid ring the fill rate of the working circuit is immediately momentarily decreased because the tube is then handling practically no fluid.

Preferably the fill tube is interconnected with the conventional scoop tube which controls the work chamber, the interconnection being such that the fill rate and empty rate are inversely varied. This arrangement facilitates work chamber liquid control by simultaneously controlling both the inlet flow to the work chamber and the outlet flow from the work chamber.

BACKGROUND The fluid drive is a member of the class of hydraulic power transmitting machinery known as hydrokinetic drives. All machines of this class depend for their operation on the kinetic energy imparted to the liquid due to centrifugal action. The fluid driveconsists of a work chamber defined by two rotating elements, a vaned impeller which transforms the energy supplied to it by the driver into kinetic energy contained in a moving mass of liquid, and a vaned runner which absorbs this kinetic energy of the fluid which is used to drive the load. The two rotating elements are mounted facing each other and are enclosed by a casing attached to the impeller. Adjustable speed fluid drives have in addition, a scoop tube and a rotating scoop chamber operable to controllably change the liquid level in the work chamber to vary the speed and torque transmitting capacity.

The amount of power that a fluid drive can transmit is a function of the amount of fluid in the impeller and runner. As the amount of fluid in this circuit decreases the amount of power that can be transmitted also decreases depending on the system loading. Since input torque must equal output torque this loss in ability to transmit power manifests itself as a decrease in speed of the runner and driven machine. Conversely an increase in the amount of fluid in the circuit increases the amount of power that can be transmitted.

Speed of response of the fluid drive is a function of how rapidly the fluid is. added to or removed from the working circuit defined by the impeller and runner. In

the conventional fluid drive, fluid is usually circulated at a constant rate to meet specific design conditions of slip, heat load absorbed by the fluid, and speed of response requirements. This in turn sets the design parameters of the scoop tubeor adjustable weir; i.e. the tube must be capable of handling the constant quantity of incoming fluid as well as that portion of the fluid in the working circuit that must be removed to decrease output shaft speed as required.

Rapid acceleration conventionally requires rapid filling of the working circuit. This entails that pumps of large capacity be incorporated in the system. However rapid deceleration requires that we must remove the fluid very rapidly. The large pumps needed for acceleration now become a detriment on deceleration. This invention proposes a variable speed fluid drive whichemploys a relatively small, lower cost pump for moving fluid into the working circuit. This incoming fluid enters a rotating reservoir casing to become an additional oil supply on demand. During rapid acceleration incoming fluid as well as reservoir fluid can be conveyed by a transfer tube into the work circuit. The converse for deceleration is true; i.e. the fluid in the working circuit is removed by the conventional scoop tube while the incoming circuit fluid is momentarily halted as the transfer tube is removed out of the fluid ring in the supply reservoir.

THE DRAWINGS The single FIGURE shows a sectional view taken on a horizontal plane through a fluid coupling embodying the invention.

GENERAL ARRANGEMENT There is shown a fluid coupling assembly 10 comprising a stationary confining tank structure 12 having four upstanding side walls l3, 14, 15 and 16. Disposed within structure 12 are two pedestals 17 and 18 which mount two

pillow blocks

20 and 21 having conventional sleeve bearings 22 through 25 therein.

Bearings

22 and 23 provide spaced radial support for an input shaft 26, while

bearings

24 and 25 provide spaced radial support for an output shaft 27. Thrust bearings 28 through 31 absorb thrust forces. A conventional vaned impeller 32 is carried by shaft 26 and a conventional vaned runner 34 is carried by shaft 27, said

vaned members

32 and 34 defining a work chamber or circuit generally defined by numeral 36.

Exhausted power transmitting liquid accumulating within the lower sump portion of tank structure 12 is continuously withdrawn therefrom by a conventional pump 38. The pumped liquid is forced through a cooler 40 and thence via a fixed pipe or duct means 42 to a stationary manifold 44 formed as an integral part of pi]- low block 20. The pumped liquid flowing for example at a rate of 500 gallons per minute, is discharged from manifold 44 into a rotating reservoir chamber 45 defined by the back wall of impeller 32 and an annular casing member 46 suitably bolted to the impeller peripheral flange 48. As the liquid discharges into reservoir 45 it is brought up to the speed of the rotating chamber by vanes 50 carried on the back wall of the impeller; additional vanes are provided at 52 and 54. The liquid is thus pumped by centrifugal action into the outer peripheral area of reservoir 45 where it is mainrelative to casing 46.

LIQUID TRANSFER INTO WORK CHAMBER The radial thickness of the liquid ring in reservoir 45 is determined by the adjusted position of a liquid transfer tube 55 slidably mounted within an acutely angled bore extending through the portion of manifold 44 immediately beneath shaft 26. The drawing is a section taken on a horizontal plane, and tube 55 as illustrated is located in a horizontal plane below the shaft centerline; it is mounted for movement in the arrow 56 direction. The location and movement of the tube is not limited to that shown.

Formed in an end of tube 55 is a liquid entrance opening 57 which acts to skim liquid from the rotating liquid ring in reservoir 45; the liquid is directed through the tube interior and thence out an exit opening 58. In the illustrated arrangement tube opening 58 resides in a slot-like cavity 60 formed in the manifold 44. The tube 55 liquid thus discharges through tube opening 58 into a stationary guide member 62, and into till pump chamber 61 having vanes 59. The liquid is then pumped by centrifugal action through openings 63 into the impeller member 32. Thus, the liquid is introduced into the work chamber or circuit 36.

Pump 38 operates continuously so there is a constant flow of liquid through duct 42 into reservoir 45. Tube 55 is thus able to continually skim off the inner boundary portions of the liquid ring within reservoir 45, and convey same into the work chamber. The work chamber liquid is given a toroidial motion as designated by the arcuate arrows, whereby to transmit power to the runner 34 and output shaft 27. A continuous liquid flow takes place from the work chamber periphery via ports 64 in the inner annular casing 65.

LIQUID TRANSFER OUT OF WORK CHAMBER Casing 65 and an additional casing 66 are bolted to impeller flange 48 to form an annular scoop chamber 67. The liquid passing through ports 64 collects in an annular ring in the scoop chamber 67. Removal of liquid from this ring is accomplished by a hollow scoop tube 68 mounted for straight line movement in the arrow 70 direction, said tube having an entrance opening 71 communicating with the scoop chamber and an exit opening 72 which discharges liquid back to the sump. Slidable mounting of tube 68 may be accomplished via a bored out boss 73 formed on the underside of a manifold 74 which is part of or connected to the stationary pillow block 21. Tube 68 may be in the same plane as aforementioned tube 55 although such location is not essential.

Scoop tube 68 removes liquid in accordance with the positionof entrance opening 71. In the illustrated posithin or shallow; the work chamber 36 is thus substanto build up in the scoop chamber 67. As this ring the rotative speed of the casings by suitable vanes 90 which counteract any tendency of the liquid to become unstable.

The drawings show tube 68 with an opening 72 discharging to they sump for subsequent passage through cooler 40. However the scoop tube could discharge directly to the cooler, as by causing the discharge opening 72 to continuously communicate with a manifold leading to the cooler; the manifold could for example merely be a hollow extension of boss COORDINATING LIQUID TRANSFER INTO AND OUT OF WORK CHAMBER Preferably

tubes

55 and 68 are operably interconnected so that one tube extends outwardly while the other tube retracts inwardly, and vice versa. Tube 68 is shown extended to the declutch position, while tube 55 is shown in the retracted position. From this position, tube 68 can move only inwardly in the arrow direction, while tube 55 can move only outwardly in the arrow 56 direction. Simultaneous movement of the two tubes may be accomplished by a first bell crank 76 pivoted at 77, a second bell crank 78 pivoted at 79, a connecting tie element 80, and two

links

81 and 82. counterclockwise force applied 'to control arm 83 causes link 81 to move tube 68 in the arrow 70 direction; simultaneously tie element is moved rightwardly to produce a counterclockwise movement of bell crank 78 and an arrow 56 movement of tube 55.

Reverse movement of arm 83 returns the

tubes

68 and 55 to their illustrated positions. In practice arm 83 may be held in any adjusted position or moved in the desired direction, depending on the desired output shaft speed or speed change.

ACCELERATION PERIOD To increase the transmission of power to shaft 27 the control arm 83 is moved counterclockwise. As this happens the opening 57 in tube 55 is moved outwardly in reservoir 45.7Opening 57 begins to handle not only the normal skim-off oil quantity provided by the flow through duct 42 but also part of the liquid ring in the reservoir; i.e. the tube opening penetrates the ring and diminishes its radial thickness, thereby momentarily causing an increased liquid flow through tube 55. This is reflected in an increased fill rate for the work chamber 36. In an illustrative example, with a pump 38 flow of 500 gallons per minute, the till tube 55 might be moved at such a rate that its opening 57 transfers 14 gallons of liquid from the reservoir ring in one second. This transfer is equivalent to 840 gallons per minute (60 X 14) so that the tube is then filling the work chamber at a total rate of about 1,340 gallons per minute. By thus momentarily utilizing the reservoir 45 liquid in combination with the output of a given pump 38 it is possible to achieve a fill rate which is much greater than that which could be achieved by the same pump 38 acting alone.

In the illustrated arrangement an increasing work chamber fill rate is accompanied by a decreasing work chamber emptying rate. Thus, as tube opening 57 is extended within reservoir 45, tube opening 71 is retracted within scoop chamber 67, thereby allowing a liquid ring thickens radially the level in the working circuit 36 builds up proportionally, thereby enabling the liquid to increasingly transmit power from the impeller to the runner.

DECELERATION PERIOD The above description generally outlines the action during output speed increase. To appreciate speed decrease action it may be helpful to visualize

tubes

55 and 68 so that opening 57 is fully extended into the reservoir 45 and opening 71 is fully retracted to the inner limit of the scoop tube chamber 67. Incremental retraction of opening 57 then tends to move said opening out of the reservoir 45 liquid ring; tube 55 thus momentarily handles less than the normal liquid flow (500 gallons in the assumed example) because part or all of the liquid from duct 42 is then used to raise the level in reservoir 45 instead of flowing into the transfer tube 55. Incremental extension of opening 71 removes liquid from the scoop chamber 67, and drops the liquid level of the work chamber. In general the speed decrease function is enhanced in the same manner as the speed increase function previously described.

GENERAL ADVANTAGES The arrangement not only produces much faster acceleration and deceleration times, but also reduces pump costs. For example, in the cited example, a five hundred gallon pump would be much cheaper than the corresponding 1,340 gallon pump required, should the reservoir 45 and fill tube 55 not be employed. The lower gallonage pump can also utilize smaller size ducting 42.

It will also be noted that over prolonged time periods the circulation losses may be less than with conventional arrangements. This is because the tubes have to handle large quantities of liquid only during acceleration and deceleration periods; at other times the tubes handle relatively small liquid flows. In contrast, conventional units require that large flows be circulated at all times.

The illustrated unit may be readily adapted for clockwise or counterclockwise movement without substantial structural alternation. This is accomplished by rotationally adjusting each

tube

55 and 68 about its longitudinal axis so that each entrance opening 57 and 71 faces the oncoming liquid in the respective chamber 45 or 67 irrespective of the rotational direction. The

respective links

82 or 81 must of course be detached from the respective tubes during the adjusting operation, and it may also be necessary to provide alternate openings 58 in tube 55 for most appropriate discharge into chamber 61. i

The design of this unit is chosen to use as much conventional structure as possible. Thus, the bearings, impeller, runner, and scoop tube 68 are conventional. New design and manufacturing effort is required only in connection with fill tube 55, reservoir 45, and a minor portion of manifold 44. Because of this it is possible to build a fast response fluid drive with very little added development time or cost as compared with the conventional fluid drive.

Should it be desired to convert the pictured unit from a fast response drive to a conventional response drive the process can be accomplished by removing casing 46 and tube 55; manifold 44 can then be replaced or openings therein plugged in a manner to cause the incoming liquid to go directly from duct 42 into cavity 60. This in effect causes the unit to function without the variable fill rate feature which gives the fast response action.

It is conceivable that in service the tube 55 and reservoir 45 may contribute some stabilizing anti-vibration effects. Such vibrations sometime occur because of the action of scoop tube 68 as it plunges into the chamber 67 liquid ring; the ring tends to be unstable because of the wake caused by tube 68. However, when reservoir 45 and tube 55 are present there is an addition of liquid into reservoir 45 coincident with the subtraction of liquid from chamber 67. This tends to shift the overhung weight towards

bearings

28 and 29, which may reduce the effect of vibrational forces otherwise present to some extent in the conventional construction.

We claim: 1. A fluid coupling comprising facing vaned impeller and runner members defining a work chamber;

means for adding liquid to the work chamber comprising a continuously operating pump and a rotating reservoir, said reservoir being carried by the impeller for continuously receiving a supply of liquid from the pump and retaining same as a rotating liquid ring;

said adding means further comprising a scoop tube extending into the rotating reservoir for continuously extracting liquid from the liquid ring; said tube being movable so that its liquid entrance opening is locatable at different radial distances from the reservoir axis, whereby the tube extracts liquid from the ring at a relatively high flow rate when the tube is plunged into the ring andat a relatively low flow rate when the tube is retracted from the ring;

said adding means further comprising a fill chamber located adjacent the fluid coupling axis and in direct fluid communication with the innermost areas of the work chamber; said scoop tube having a liquid exit opening continuously communicating with the fill chamber in all positions of the tube, whereby the liquid handled by the tube is directed from the tube through the fill chamber and thence into the work chamber.

2. The coupling of claim 1 wherein the scoop tube comprises a straight tube mounted for rectilinear movement in the direction of its length; said tube being adjustable about its longitudinal axis so that its liquid entrance opening faces in either of two directions, the arrangement of said tube accommodating clockwise or counterclockwise rotation of the coupling.

'3. The coupling of claim 1 and further comprising a sump-cooler means, and means for withdrawing liquid from said work chamber; said withdrawing means comprising a rotating scoop chamber means continuously receiving liquid from the work chamber, the liquid being maintained as an annular liquid ring in the outer portions of the scoop chamber; said withdrawing means further comprising a second scoop tube operable to convey liquid out of the scoop chamber to the sumpcooler means, and mechanical means for moving the second scoop tube so that it is able to convey liquid from the scoop chamber at a variable rate.

4. The coupling 06551155 and further comprising I movement in the direction of its length; each tube being adjustable about its longitudinal axis without disturbing the aforementioned linkage, the arrangement permitting each tube to have its liquid entrance opening face in either of two directions, thereby accommodating clockwise or counterclockwise rotation of the coupling.

7. The coupling of claim 5 and further comprising an input shaft connected with the impeller member, and

an output shaft connected with the runner member; bearings supporting said shafts in axial alignment with one another; said reservoir being carried on the impeller in surrounding relation to an impeller shaft hearing whereby to move the center of gravity toward the inboard impeller bearing.

8. The coupling of claim 3 wherein the reservoir takes the form of a casing formed separately from the impeller and runner members; said impeller having a peripheral flange, and said reservoir casing having a cooperating flange removably secured thereto; the first scoop tube being removably mounted within the coupling by means of a hollow manifold having a liquid-accepting cavity therein; the removable nature of the reservoir casing and first scoop tube permitting the coupling to be used without the variable till rate feature.

9. The coupling of claim 1 wherein the rotating reservoir is provided with internal pumping vanes operable to preclude any substantial circumferential slippage between the ring and reservoir.

Claims

1. A fluid coupling comprising facing vaned impeller and runner members defining a work chamber; means for adding liquid to the work chamber comprising a continuously operating pump and a rotating reservoir, said reservoir being carried by the impeller for continuously receiving a supply of liquid from the pump and retaining same as a rotating liquid ring; said adding means further comprising a scoop tube extending into the rotating reservoir for continuously extracting liquid from the liquid ring; said tube being movable so that its liquid entrance opening is locatable at different radial distances from the reservoir axis, whereby the tube extracts liquid from the ring at a relatively high flow rate when the tube is plunged into the ring and at a relatively low flow rate when the tube is retracted from the ring; said adding means further comprising a fill chamber located adjacent the fluid coupling axis and in direct fluid communication with the innermost areas of the work chamber; said scoop tube having a liquid exit opening continuously communicating with the fill chamber in all positions of the tube, whereby the liquid handled by the tube is directed from the tube through the fill chamber and thence into the work chamber.

3. The coupling of claim 1 and further comprising a sump-cooler means, and means for withdrawing liquid from said work chamber; said withdrawing means comprising a rotating scoop chamber means continuously receiving liquid from the work chamber, the liquid being maintained as an annular liquid ring in the outer portions of the scoop chamber; said withdrawing means further comprising a second scoop tube operable to convey liquid out of the scoop chamber to the sump-cooler means, and mechanical mEans for moving the second scoop tube so that it is able to convey liquid from the scoop chamber at a variable rate.

4. The coupling of claim 3 and further comprising means operably connecting the first and second scoop tubes so that the first scoop tube increases its fill rate while the second scoop tube decreases its extract rate, and vice versa.

5. The coupling of claim 4 wherein the aforementioned connecting means comprising a linkage which causes one tube to move its entrance opening toward the rotational axis while the other tube moves its entrance opening away from the rotational axis, and vice versa.

6. The coupling of claim 5 wherein each scoop tube comprises a straight tube mounted for rectilinear movement in the direction of its length; each tube being adjustable about its longitudinal axis without disturbing the aforementioned linkage, the arrangement permitting each tube to have its liquid entrance opening face in either of two directions, thereby accommodating clockwise or counterclockwise rotation of the coupling.

7. The coupling of claim 5 and further comprising an input shaft connected with the impeller member, and an output shaft connected with the runner member; bearings supporting said shafts in axial alignment with one another; said reservoir being carried on the impeller in surrounding relation to an impeller shaft bearing whereby to move the center of gravity toward the inboard impeller bearing.

8. The coupling of claim 3 wherein the reservoir takes the form of a casing formed separately from the impeller and runner members; said impeller having a peripheral flange, and said reservoir casing having a cooperating flange removably secured thereto; the first scoop tube being removably mounted within the coupling by means of a hollow manifold having a liquid-accepting cavity therein; the removable nature of the reservoir casing and first scoop tube permitting the coupling to be used without the variable fill rate feature.