US3100966A - Fluid drive - Google Patents

Description

2 Sheets-Sheet 1 ATTORNEYS R. M. NELDEN FLUID DRIVE Allg. 20, 1963 Filed June 25, 1960 Aug. 20,1963 R. M. NELDEN 3,100,966:

FLUID DRIVE Filed June 23, 1960 2 Sheets-Sheet 2 TOR.

INVEN RICHARD M. NELDEN w1LsoN,Lew\s MCRAE ATTORNEYS.

United States Patent O 3,100,966 FLUID DRIVE Richard M. Nelden, Birmingham, Mich., assignor to American Radiator & Standard Sanitary Corporation,

New York, N.Y., a corporation oi Delaware Filed June 23, 196i), Ser. No. 38,160 8 Claims. (Cl. ell-54) This invention relates to va fluid drive, and particularly to a variable 'speed uid drive having improved means for partially or Wholly declutching Ithe runner during periods of impeller acceleration and .output shaft overload. In conventional duid drive arrangementsoi the variable :speed type there is employed a vaned impeller and a lvaned runner cooperating together to deiine a work chamber, Thel impeller is carried by the input shaft which may be directly or indirectly driven by a prime mover such `as an electric motor or gasoline engine.Y The runner -is connected to the output sha-ft ywhich drives the load. A .iluid-conning casing extends around and beyond the impeller and runner to define a. chamber for receiving the power lduid from :the work chamber. This receiving chamber houses a fluid-withdrawing means which in the usual case consists of one :or more scoop tubes which `dip into the -iluid within the chamber Iand convey the uid out of the fluid coupling and thence into `a sump. The sump supplies hot fluid to a pumping mechanism which circulates all or part` of the tluid through -a cooler structure before returning it` into the work chamber defined by the aforementioned runner and impeller.

It will be understood thatthe dri-ve from the yaned impeller to the vaned run-ner is derived from the rapidly whirl-ing or vortically travelling iluid located with-in the work chamber. With relatively small quantities of fluid Within the work chamber the motion of the impeller is only partially transmitted to the runner, ie., there is a slippage, which may vary depending on the fractional extent to which the work chamber is iilled. When the work chamber is completely lilled the slip is at a minimum, and there is substantially a fone-to-one drive from the impeller to .the runner.

The fluid level in the work chamber is determined by the position of the previously mentioned scoop tubes which are -located in the scoop chamber. In the usual case an externa-l control is provided `for determining the position of these scoop tubes, the arrangement being such that when the control is suitably operated to dispose the lips of the scoop tubes adjacent the outer periphery of the scoop chamber the fluid level is reduced so as to correspondingly reduce the operating level in the work chamber. When the control is actuated to dispose the scoop tube lips away from the :outer periphery of the scoop chamber the level of `the tluid ring is increased so `as-to accordingly increase the @lling of the work charnber and thereby reduce the slip existing between the imeller and runner.

During certain operational periods of the lluid drive, as tor --example during periods `of impeller acceleration and during other periods of output shaft overload, it is desirable to partially or wholly disconnect the -impeller [from .the runner. The impeller-runner connection is, as previously explained, provided by the iluid within the work chamber, and accordingly the declutching action is necessarily obtained by an emptying of the work chamber. `It will be understood that as `an overload condition occurs on the output shaft the emptying of the work chamber should be eiiected rather rapidly in order to prevent breakage 4or wear of parts in the power system.

Also, Ithe iluid declutching :action should preferably be 3,100,966 Patented Aug. 20, 1963 :automatic and without necessity for actuation by human intervention or human control.

lt is an object of the present invention to provide a uid drive with Ia declutching mechanism having the above-mentioned desirable automatic characteristics.

A `further `object of the invention is to provide a fluid drive with :a torque limiting or declutching mechanism which is of relatively simple construction and which, without extensive redesign, can be built to come into play at any desired percentage of slip between the impeller and runner.

It is a further object ofthe invention to provide a fluid drive with ya Vdeclu-tching mechanism, the design of which is such as to permit it to empty the work chamber quickly or more slowly, the exact rate of emptying being varied by means of an easily effected structural alteration of the mechanism. f

A further object of the invention is to provide a declutching mechanism which can be operatively utilized with a variable speed fluid drive, `and which during normal operation of the lluid drive is ineffective to have any dlsadvantageous action on the fluid drive performance.

A general object of the invention is to provide a iiuid drive with a declutching device having low manu-factur- .ing and maintenance costs.

Other objects of this invention will appear in the l following descrip-tion and appended claims, reference being the coupling show-n in operative posi-tion in a Huid circul-ating system;

FIG. 2 is a sectional view taken substantially on line 2-2 in FIG. l. Y

Before explaining the present invention in detail, it is to be understood that thel `invention is not limited in its applica-tion to the details of construction and arrmgement of parts illustrated in the `aoco-mpanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways'. Also, it is to be understood that the phraseclogy or terminology employed herein is Ifor the purpose of description and not of limitation.

Referring to FIG. 1 of the drawings, there is disclosed ya fluid drive including :a bottom or base wall 10 having an opstanding casing structure v12 secured thereto. The casing :structure comprisesca top Wall 14, a pair of side walls 16, and a pair of end walls or bells. 18 and 20. The end bells are removably but ixedly carried on vertical -vvall structures v22. and 24, the arrangement being such as to permit :the end bells to be removed for inspection, replacement `and repair of 4the fluid coupling components disposed within the casing structure.

End bell '18 mounts the beaming assembly 26 Ifor the input shaft 28. End bell 20 mounts the bearing assemblies 30 and 31 for the output shaft 32. -Bell 20 comprises two component parts numbered in the drawings as 21 and 23. Component 21 mounts `anti-friction bearing :assembly 30 for shaft 32, and component 23 mounts sleeve bearing `31 for shaft 32. It will be understood Ithat the bearingcnd lbell relationships can be varied, and that the `showings in the drawings are merely illustrative. The illustrated input shaft 28 is hanged `as at 314 to -form ya mount rior the impeller casing 316 and impeller 3S. As shown in FIG. 1 the impeller casing extends beyond the impeller `and is of a two-section construction. Section 42 of the casing extends inwardly as at 44, and `a partition 48 is suitably carried on the casing so `as to cooperate therewith `in deining a scoop chamber 46. A series of an ex-ternal con-trol `structure.

3 openings 5G are provided at the periphery of the partition to permit fluid to flow into the scoop chamber from the work chamber.

The work chamber is definedtby the `aforementioned impeller 33 and the runner 52, each of the impeller and runner having la series of radial vanes as at 54 and Se, said vanes being radially arranged as in the conventional practice.

`In the illustrated embodiment the work chamber defined by the impeller and runner is supplied ywith workinguid from a lluid lline 53, said line ybeing connected to the work chamber via `an annular chamber 6tlg a passageway 62 within the input shaft 2S, and a passageway X64 located within the impeller. It will be understood that during rotation of the input shaft the fluid which is introduced into the space between impeller vanes 54 is given a vortical or whirling motion as indicated generally by :the arrows 65.

The huid is thrown centrifugally outwardly and travels between the impe-ller and runner vanes `so as to ltransmit power from the impeller to the -runner. Fluid occupies the annular space `68 and circulates through the openings Stb into the :scoop chamber 46. The level of fluid within the scoop chamber is determinative of the amount or" fluid within the work chamber, and las previously explained, the amount `of fluid 'in the work chamber determines the extent of slip which exists between the impeller and runner,

To control and vary the quantity of lluid within the work chamber Iand s-coop chamber there is provided a fluid-withdrawing means, shown in the illustrative embodiment as a Iscoop tube 76, said tube being of hollow con- `struction andhaving la lip area 72 which dips into the scoop tube lluid into the `sump designated generally by the numeral 86. The exact construction and mounting of the lscoop tube may Ibe varied insofar `as the present invention is concer-ned.

Thetentire system is installed with a sufficient amount of fluid Ito provide a sump liquid level 87 su'icient to form a source of lluid vfor the fluid pump 88. lhe pump may be of various different constructions, las for example `a vane type construction, land may be powered in lvarious different way-s. One convenient method of powering the pump consists of employing a chain 90 trained around a sprocket 92 on input shaft t28 and a `sprocket 94 on the pump shaft 96. The pump may be supplied with liquid through a port adjacent its lower end, and the liquid output may be directed through -a conduit `98 into the -conventional cooler |100. The cooled fluid may be then directed into the aforementioned line 58 and thence back to the impeller via the aforementioned passageways 62 and 64. A

suitable diverter valve 59 may be provided for Adirecting V77, the teeth of which mesh with the teeth of a toothed Y operator rack lill carried on a slidable shaft lll-3. lt will be understood that the rack-shaft means extends through and within the end bell 2li so as to be moved by This control structure may merely consist of a manually operable handle or actuator, or it may be operate-d automatically in response to variation in a particular control condition such as temperature change or fluid pressure development. The present invention is not concerned with the type of control structure employed, and hence details thereof Iare not illustrated.

` which is provided with la passage `82 -for directing the It will be understood that while the drawings show the fluid-withdrawing device as consisting of a rotary scoop tube 70, yet other types of fluid-withdrawing constructions such as rectilinearly mov-able scoop tubes can be employed. irrespective of the type of fluid-withdrawing means which is employed, it will be seen that during operation of the fluid drive the torque transmission from the iimpeller to the runner is determined by the amount of fluid in the scope chamber. With any substantial quantity of fluid in the work chamber, acceleration of the input shaft applies an added load on the output shaft. However, with the construction of the present invention .special provision is made for avoiding any undesired load onto the output shaft during this acceleration period. In this connection it will be noted that the runner is provided with a series of protruding wall portions 104 arranged around its periphery. These wall portions are bored out to form the short circumferentially extending passageway sections lilo. Longer radial passage sections ltlt extend from sections 16",?, and short axial passage sections lll@ extend from the radial sections. The three connected sections ltl, lli and 1l@ constitute a passage` way herein designated by numeral 195.

ln operation of the fluid drive, during periods of input shaft acceleration the impeller is rotating faster than thel runner and the fluid which is discharged into the annular space 63 is constantly overtaking the passage sections 166.

The velocity head of the fluid in space 68V is at this timeV sufcient to force the fluid to ilow into the passage sections ltl and thence be directed axially as at 110 out of the Vfluid coupling. The passageway fluid may be discharged into the sump, either directly through the casingeye lll or by first discharging into the scoop chamber. The nature of the discharge from passage sections liti depends on such factors as the magnitude of the velocity head, the magnitude of the centrifugal head, and the size `of the pasageway. `In the illustrated embodiment each of the passage sections dit) is formed by an annular insert nozzle element 13, and it lwill be understood that all or some of the pasageways ltl may be effectively varied in size by suitable nozzle element construction procedures. By this arrangement lluid couplings having different operating characteristics can be obtained fat very low added cost. c

In use of the illustrated drive, during the acceleration period the amount of lluid within the work chamber will be somewhat less than the level which would ordinarily be dictated by the scoop tube 7@ (due to the action of the passageway There will therefore be a substantial declutching of the 'runner such as to provide a torque limiting action sufficient to safeguard the output shaft land provide a soft satisfactory acceleration action.

It will be understood that as the fluid drive comes up to speed the runner speed will approcah the impeller speed and the lluid within the space 63 will not have sufcient velocity head to overtake the passages 105. The passages will thereby not interfere with the normal operation of the lluid drive under usual operational conditions.

As previously explained, in the presence of certain overload conditions on the output shaft it is desirable to declutch the runner from the impeller in order to prevent parts damage. With the illustrated device, in the event of an overload condition on the output shaft 32 the runner will necessarily reduce its speed, and the fluid within the space 68 will thereby be permitted to overtake the passageways lliS and flow inwardly therein so as to be discharged from the working circuit. The subtraction of the fluid from the work chamber through the passageways lt' serves to partially or wholly declutch the runner from the impeller and thereby prevents the overload condition on shaft 3-2rrfrom having any adverse effect on the component mechanisms. Y

The time period necessary for effecting this declutching action is determined by the size and length of the passageways in relation to the other mechanisms of the fluid drive, and it will be understood that in general the speed of declutching may be increased by increasing the size of the passageways and decreasing their length. The size of the passageways may be increased by increasing the total number of passageways and/ or increasing the crosssectional area of each passageway. In the illustrated construction the cross sectional area of each passageway may be readily controlled by utilizing appropriate size inserts 113.

By choosing a suitable length for the passage sections 108 the declutching action can be set to come into play at any desired percentage of slip. This, if the passage sections 8 extend only a short distance inwardly from the outer periphery of the runner the velocity head of the uid will be suihcient on a relatively small differential speed between impeller and runner to exhaust fluid from the work chamber in a manner to declutch the runner from the impeller. Under these conditions the declutching action will take place at arelatively small slip between the impeller and runner. By making the passage sections '108 extend further toward the axis of the fluid drive the lluid at `68 must aquire a relatively large velocity head before it can suliciently overtake the passageways 105 so as to be exhausted from the work circuit. Therefore, under these design conditions the declutching action -will take place at a relatively high percent of slip between the -impeller and runner.

If desired certain ones of passage sections Q08 may extend further radially inward than others, as for example as shown in FIG. 2 wherein four of the eight passage sections terminate inwardly of the other four. This passage arrangement is of advantage in that it permits a gradual, smooth declutching action, i.e. at a relatively small speed dilerential the shorter ones of passage sections '108 become operative and at a larger speed differential the longer ones of passage sections `108 become operative.

The `drawings show the exhaust passageways 1G35 directly in the body of the runner. However, it will be appreciated that these passages could be formed by other means. For example, these passageways could if desired be constructed as separate tubes fastened onto the back of the runner. With such a construction the outer surfaces of the tubes could be made to have the desirable function of acting 4as fluid-engageable driving vanes for the runner.

Various other changes could be made without departing from the spirit of the invention as delined in the appended claims.

I claim:

l. In a uid coupling, a-housing dening a liquid reser- Voir,

a toroidal work chamber within said housing comprising opposed axially aligned and spaced rotatable impeller and runner shells, mounted respectively on input and output shafts,

means for continuously supplying liquid to said work chamber from said reservoir,

a casing connected to said impeller shelland enclosing said runner shell in `spaced relation to form one wall Aof a rotatable scoop chamber,

a radial partition wall carried by said casing between said one wall and said runner to form the other wall of the scoop chamber and separate said work chamber from said scoop chamber, said casing and partition walls being spaced radially from said output shaft to form coaxial eyes opening from said Work chamber into said housing and thus to said reservoir,

said scoop chamber being coaxial to said work chamber and in free liquid communication therewith whereby the level of liquid in said scoop chamber determines the amount of liquid in said work chamber and the slip in said coupling,

a scoop tube supported for radial adjustment in said scoop chamber land discharging to said reservoir for 5 controlling the amount of yliquid in said scoop chamberand thus in said Work chamber,

means for -adjusting said scoop tube,

scoop passage means extending radially inwardly through said runner from an inlet mouth in said work chamber `at the periphery of said runner to an exhaust opening in the runner hub adjacent said output shaft,

and said exhaust opening extending axially to discharge the liquid through said eyes and into said housing during predetermined slip when said impeller appreciably overruns said runner.

2. In -a lluid coupling including 4a housing delining a liquid reservoir,

a toroidal `work chamber within said housing comprising opposed axially aligned and spaced rotatable impeller and runner shells,

means for continuously supplying liquid to said work chamber from said reservoir,

a casing connected to said impeller shell and enclosing said runner shell in spaced relation to form one wall of a rotatable scoop chamber,

a partition .wall carried by said casing between said one wall and said runner to form the other Wall of said scoop chamber,

said casing and partition walls having eyes coaxial to said work chamber 4and opening from said -work chamber into said housing,

said scoop chamber being coaxial to said work chamber and in free liquid communication with said work chamber whereby the level of liquid in said scoop chamber determines the amount of liquid in said work chamber and the slip in said coupling,

a scoop tube supported for radial adjustment in said scoop chamber and discharging to said reservoir for cont-rolling the amount of liquid in said scoop chamber and thus in said work chamber,

and means for adjusting said scoop tube,

the improvement of overload scoop passage means extending through said runner yfrom an inlet mouth in said work chamber at the periphery of `said runner to Ian exhaust opening in alignment with said eyes of said casing and partition walls,

and said exhaust opening being oriented to discharge through said eyes Vand into said housing during predetermined slip when said impeller overruns said runner.

`3. In a lluid coupling including a toroidal work chamber comprised of opposed mpeller and runner shells,

means for continuously supplying Working liquid to said work chamber,

a casing connected to said impeller shell and enclosing said runner shell in spaced relation to form a rotatable scoop chamber,

said scoop chamber having an eye coaxial to said work chamber,

said scoop chamber being coaxial to said work chamber land in free liquid communication with said Work chamber whereby the level of liquid in said scoop chamber determines the amount of liquid in said work chamber and the slip in said coupling, 4

a scoop tube adjustable in said scoop chamber and discharging to said supply means for controlling the amount of liquid in said scoop chamber and thus in said work chamber,

and means for adjusting said scoop tube,

the improvement of a passage extending through said runner from an inlet mouth at the periphery of said runner to an exhaust opening positioned radially inwardly of said inlet mouth,

and said exhaust opening being oriented to discharge through said eye during predetermined slip conditions when said coupling appreciably overruns said runner,

arcanes and means for conducting said discharged luid to said supply means.

4. lIn a fluid coupling including a toroidal work chamber comprising opposed impeller and runner shells,

means for contiuously supplying Working liquid to said work chamber, Y

casing means connected to said impeller shell to orm a rotatable scoop chamber coaxial to said work chamber and in tree liquid communication therewith whereby the level of liquid in said scoop chamber determines the amount of liquid in said work chamber and the slip in said coupling,

said scoop chamber having an axial opening,

a scoop tube adjustable in said scoop chamber and discharging to said supply means for controlling the amount of liquidin said scoop chamber and thus said work chamber,

I and means for adjusting said scoop tube,

the improvement of scoop passage means extending through the back of said runner from an inlet mouth in said work chamber at the peripheral level of said runner to an exhaust opening centrally of lsaid runner,

and said exhaust opening being oriented to discharge through said axial opening of said scoop chamber during predetermined slip conditions when said impeller overruns said runner.

'5. In a fluid coupling,

a housing dening a liquid reservoir,

a toroidal work chamber in said housing comprising opposed axially aligned and spaced rotatable impellcr and runner shells, Y

meansfor supplying liquid to said work chamber from said reservoir,

a casing connected to said impeller shell and enclosing said runner shell in spaced relation to form one Wall of a rotatable scoop chamber,

a partition wall carried by said casing between said 'one wall and said runner to form the other wall of the scoop chamber,

said partition wall having an eye coaxial to said work chamber and opening from said work chamber into said scoop chamber,

said scoop chamber being coaxial to said work chamber and in free liquid communication with said work chamber whereby the level of liquid in said scoop chamber determines the `amount of liquid in said work chamber and .the slip in said coupling,

a scoop tube adjustable in said scoop chamber and discharging to said reservoir to control the amount of liquid in said scoop chamber and thus in said work chamber,

means for adjust-ing said scoop tube,

-a declutch passage extending from yan inlet mouth positioned at the peripheral level of said runner to an exhaust opening positioned radially inwardly of said inlet mouth,

and said exhaust opening being oriented to discharge through said eye during predetermined slip condi tions of said impeller overrunning said runner.

6. I-n a fluid coupling,

f a toroidal work chamber dened by opposed impeller and runner shells,

means for continuously supplying liquid to said work chamber,

casing means connected to said impeller shell and enclosing said runner shell in spaced relation to form la rotatable chamber to hold a rotating ring of liquid,

said rotatable chamber being coaxial to said work chamber and in free liquid communication therewith whereby the level of liquid in said rotatable chamber determines the amount of liquid in said work chamber and the slip in Said coupling,

adjustable regulating means for regulating the quantity of liquid in said rotatable ring and thereby the amount of liquid in said work chamber,

declutch passage means extending from an inlet mouth at the peripheral level of` said runner to an exhaust `opening positioned between said coupling axis and said inlet mouth,

and said exhaust opening being oriented to discharge liquid out of said work chamber and back to said supply means.

7. In a fluid coupling,

a toroidal Work chamber defined by opposed impeller and runner shells,

means' for continuously supplying Working liquid to said work chamber,

casing means connected to saidimpeller shell and enclosing said runner shell in spaced relation to form `an annular rotatable chamber to hold a rotating ring of liquid,

said rotatable chamber being coaxial to said wonk chamber and in free liquid communication therewith whereby the level of liquid in said rotatable chamber determines the amount of liquid in said work chamber and the slip in the coupling,

adjustable regulating means for regulating the quantity of liquid in said rotatable'ring `and thereby the amount of liquid in said work chamber,

a plu-rality lof declutch passages, each having an inlet mouth at about the outer peripheral level of said impeller and runner shells in said work chamber and extending to an exhaust opening between said coupling axis and said inlet mouth,

at least sOme of said exhaust openings being positioned nearer the axis of said coupling than others,

said exhaust openings being oriented to discharge liquid out of said Work chamber and back to said supply means,

and means for recycling liquid discharged from said exhaust openings back rto said work chamber.

8. n a iiuid coupling,

a toroidal Work chamber definedl by opposed impeller and runner shells,

means for supplying working liquidto said work at about the outer penipheral level of said runnerV to an exhaust opening positioned between said coupling axis and said inlet mouth.

said exhaust opening being oriented to discharge liquid out of said work chamber and back to said supply means,

and means for recycling liquid exhausted from said discharge opening back to said work chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,672,232 Saives June 5, 1928 2,127,738 Kugel Aug. 23, 1938 2,187,656 Kicp et al Jan. 16, l1940 2,690,052 oding sept. 28, 1954 2,784,555 Anderson Mar. 12, 1957 2,880,583

Sinclair Apr. 7, 1959

Claims (1)

1. 6. IN A FLUID COUPLING A TOROIDAL WORK CHAMBER DEFINED BY OPPOSED IMPELLER AND RUNNER SHELLS, MEANS FOR CONTINUOUSLY SUPPLYING LIQUID TO SAID WORK CHAMBER, CASING MEANS CONNECTED TO SAID IMPELLER SHELL AND ENCLOSING SAID RUNNER SHELL IN SPACED RELATION TO FORM A ROTATABLE CHAMBER TO HOLD A ROTATING RING OF LIQUID, SAID ROTATABLE CHAMBER BEING COAXIAL TO SAID WORK CHAMBER AND IN FREE LIQUID COMMUNICATION THEREWITH WHEREBY THE LEVEL OF LIQUID IN SAID ROTATABLE CHAMBER DETERMINES THE AMOUNT OF LIQUID IN SAID WORK CHAMBER AND THE SLIP IN SAID COUPLING, ADJUSTABLE REGULATING MEANS FOR REGULATING THE QUANTITY OF LIQUID IN SAID ROTATABLE RING AND THEREBY THE AMOUNT OF LIQUID IN SAID WORK CHAMBER, DECLUTCH PASSAGE MEANS EXTENDING FROM AN INLET MOUTH AT THE PERIPHERAL LEVEL OF SAID RUNNER TO AN EXHAUST OPENING POSITIONED BETWEEN SAID COUPLING AXIS AND SAID INLET MOUTH, AND SAID EXHAUST OPENING BEING ORIENTED TO DISCHARGE LIQUID OUT OF SAID WORK CHAMBER AND BACK TO SAID SUPPLY MEANS.

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