US2924942A

US2924942A - Hydraulic turbo couplings

Info

Publication number: US2924942A
Application number: US668243A
Authority: US
Inventors: Sinclair Harold
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-07-02
Filing date: 1957-06-26
Publication date: 1960-02-16
Anticipated expiration: 1977-02-16

Description

Feb; 16, 1960 Fil ed June 26, 1957 H. SINCLAIR HYDRAULIC TURBO COUPLINGS 2 Sheets-Sheet 1 IN VEN TOR Ham /d 5/770/5/7 ATTORNEY Feb. 16, 1960 y H. SINCLAIR 2,924,942

HYDRAULIC TURBO COUPLINGS Filed June 26, 1957 2 Sheets-Sheet 2 Fig.2.

. woe/(W6 IN VE N TOR United States are 2,924,942 nYnRAULrc TURBO COUPLINGS Harold Sinclair, Windsor, England Applicationlune 26,1957, Serial No. 668,243 "Claims priority, application Great Britain July 2, 1956 Claims. ((31. 60-54) This invention'relates to hydraulic turbo couplings which are provided with one or more quick-emptying valves for enabling the working chamber to be rapidly emptied, the said valve or each valve comprising a valve element that controls an outlet port and which is subject on one side to the centrifugal pressure of the working liquidin the. working chamber, and on the other side to the pressure of working liquid fed to the said other side of the valve from a passage wherein the liquid is subject to centrifugal head. In the normal operation of the turbo coupling the closing force on the valve due to the centrifugal head acting on the radially outer side of the valve element, e.g. a diaphragm, is greater than the opening force resulting from the pressure acting on its inner side, 'due to the exposed area of the outer side of the valve element being considerably greater than the exposed area on the inner side, and the valve element, e.g., a diaphragm, is thereby applied to a valve seat whereby the said portis closed. Provision is made for theworking liquid continuously supplied through the said passageto the said outer side of the diaphragm to leak away continuously at a restricted rate through a leak-off nozzle. When the working chamber is to be emptied, the supply of working liquid to the said passage is discontinued, so that after a short time lag determined inter .alia by the flow area of the leak-off nozzle, the pressure on the diaphragm due to the liquid fed through, said passage is overcome by the centrifugal pressure' of the liquid in the working chamber, so that the valve element is moved from its seat and the port is opened, thereby enabling the working chamber to empty rapidly through the said port.

When the turbo coupling is driven by a constant speed prime mover, e.g. an electric motor, the abovementioned time lag at the normal working temperature is substantially the samefor each emptying operation. Where, however, the impeller of the coupling is arranged to be driven atdifierent speeds, for example by a diesel engine with 'variable speed control, the said time lag will be different for different impeller speeds, being longer for lower impeller speeds, for the reason that with a reduction in coupling speed the effect of centrifugal force is reduced and the rate of emptying, through the leak-ofi nozzle is correspondingly longer. When the coupling is operating at low speed the timelag between the cutting off of the supply of liquid to the said passage and the opening of the diaphragm valve may be considerable. Obviously a short time lag is desirable, and it is the ob ject of the present invention to provide a turbo coupling which is provided with one or more quick-emptying valves with an improved leak-off nozzle arrangement such that the time lag is less dependent on the coupling speed than has hitherto been the case.

According to the present invention there is provided a hydraulic turbo coupling provided with at least one quickemptying valve'for enabling the working chamber of a valve element that controls an outlet port and which I is subject on. one side to the centrifugal pressure of the coupling to be rapidly emptied, said valve comprising the working liquid in the working chamber and on the other side to the pressure of liquid fed to the said other side of the valve element from a passage wherein the liquid is subject to centrifugal head when theturbo coupling is in operation, means enabling liquid to leak off from the said other side of said valve element, the turbo coupling also including meansfor controlling the supply of liquid to said passage, characterised by'the provision of meansresponsive to the angular speed of said -quick-emptying valve for varying the flow area of said leak-off means in such sense that when said speedresponsive means are operative the pressure on the said other side of the valve element can fall more rapidly in response to cuttingoffof the supply of liquid to said passage than it would do if said means were not provided.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, as applied to a hydraulic turbo coupling of the type in which the supply of working liquid to the working chamber is effected by means of an adjustable scoop tube slidable within a scoop tube housing that is stationary and is disposed in a rotatable reservoir chamber which receives the liquid flowing from the working chamber.

In the drawings, Fig. 1 is a view of the turbo coupling in sectional elevation, taken through the axis of the coupling, and Fig. 2. is a sectional view, on a larger scale, of one of the diaphragm valves with which the turbo coupling is provided.

Referring to the drawings, the turbo coupling shown comprises a vaned impeller 1 and a vaned runner 2 mounted respectively on an input shaft 3 and an output shaft 4, the impeller. and runner being disposed within a casing 5 that rotates with the impeller 1, and which isprovided at its outer periphery with a plurality of diaphragm quick-emptying valves 6 spaced uniformly around its axis of rotation.

In the following detailed description of one of the valves 6 it will be assumed that the angular position of the working chamber within the casing 5 is such that the valve 6 in question is at the top of the casing 5 as shown in Fig. 1. The valve 6 comprises in Fig. 2, a substantially cylindrical valve body 7 with a central aperture 8, the valve body 7 being secured to the outside of the casing 5 with the aperture 8 centrally disposed with respect to a larger aperture 9 in the casing 5. The valve body 7 has inner and outersubstantially cylindrical walls 10 and 11 with an annular space between them. A composite ring comprising inner and

outer ring members

12 and 13 with an annular guide 14 clamped between them, is screwed into the outer wall of the valve body 7 with the coplanar lower surfaces of the

ring members

12 and 13 spaced from the bottom wall 15 of the valve body 7 and with theupper surface of the inner ring member 12, which projects inwardly from the annular guide 14, in the same plane as theupper surface of the inner wall 10 of the valve body, and spaced laterally therefrom. The upper surfaces of the inner Wall 10 of the valve body 7 and of the inner ring member 12 form seats for a diaphragm disc 16 made froma disc of thin sheet metal, which normally rests on the said valve seats, its movement away from the seats being limited by an annular step formed by an inwardly projecting flange 17 .on the outer ring members 13.

There is also screwed into the valve body 7, aboveand spaced from the composite ring 12, 1'3, 14, a cover plate 18 in the center of which is screwed: a plug' 19 having a discharge port2tl of small diameter, the plug19 serving as a leak-off'nozzle. The cover plate 18 also has two centrifugal control nozzles 21 screwed intuit, one onxeach side of the plug '19. Eachcentrol nozzle comprises a 3 if plug 22 which has a cavity 23 that is in tron at its lower end with the interior of the valve body 7 and which at its upper end merges into a port 24 that communicates with lateral discharge ports 25 extending.

through the head of theplug '22, the head being. disposed outside the cover plate 18. A ball 26 in the cavity 23 is adapted, when in its upper position, i.e., its radiallyoutermost position with respect to the axis of rotation of. the turbo coupling, to close the port 24. A valve spring 27 tends to move the ball 26 away from the said upper position. The springs 27 of the two control nozzles 21 are of different strengths, for a reason'that will be explained;

The space .28 within the valve body 7 below the composite ring and between the walls 10 and 11 communicates with the exterior of the casing of the working chamber of the turbo coupling via a plurality of discharge openings 29 of large area in the valve body 7, and the space 28 also communicates with the central space 8 bounded laterally by the inner wall of the valve body 7, and thus with the interior of the working chamber of the turbo coupling, via' a port 30 of small diameter in the inner wall 10, the said port serving in place of a conventional leak-off nozzle. An inlet port 31 is formed in the outer wall 11 of the valve body 7, the port'31 communicating with the space 32 above the diaphragm 16.

Referring to Fig. 1, the turbo coupling is of the scoop control type, i.e., it is provided with a reservoir chamber 33 that rotates with the casing 5 of the working chamber and therefore with the impeller 1, and an adjustable scoop tube 34 is provided for feeding working liquid from the reservoir chamber 33 to the working chamber via a cooler (not shown). The scoop tube 34 is adjustable longitudinally in a scoop tube housing 35, by means of a control lever 36. Turbo couplings of this general type are well known and are shown for example in patent specification No. 2,187,667. The reservoir chamber 33 encloses the diaphragm valves 6. The working liquid coming from the cooler passes through a duct 37 in the said scoop tube housing 35, the duct 37 leading to an annular collector groove 38 formed in the scoop tube housing 35 adjacent the casing 5 of the working chamber. The casing 5 is formed with a plurality of inlet ports 39 spaced uniformly around the coupling axis and in communication with the collector groove 38. A dished annular collector ring 40 is mounted on the casing 5 outside the said inlet ports, the collector ring having a part conical wall which is connected to the casing 5 towards and pro'jects from it towards the coupling axis and which leads to a fiat end wall which projects radially inwards to a short distance from the scoop tube housing 35, so that the collector ring 40 incloses the annular collector groove 38 and the inlet ports 39. The part conical wall of the collector ring isformed with a plurality of holes, corresponding in number to the number of diaphragm valves 6, and from each of the holes a feed tube 41 leads over the outer wall of the casing 5 to the abovementioned inlet port 31in the outer wall 11 of each diaphragm valve body 6. To the inner.

surface of the part-conical wall of the collector ring is secured a guide ring 42 which serves to guide working liquid to the feed tubes 41, constituting a passage wherein the liquid is subject to centrifugal head.

In the operation of the turbo couplingat full speed, the scoop tube 34 is fully extended, as shown in Fig. 1. Working liquid passes continuously from the working chamber of the coupling through the apertures 9 and the central opening 8 of each valve body 7, through the restricted port 30 in the inner wall 10 of each valve body 7, and thence through the discharge openings 29 in the outer walls 11 to the rotating reservoir chamber 33. It there forms a ring of liquid, from which liquid is picked up continuously by the extended scoop tube34 and is fed via the co'oler to the duct 37 and thence to thecollector groove 38, whence some of the liquid is deflected by the guide ring to the feed tubes 41, through which it passes to the inlet ports 31 in the valve bodies 7 and to the free communicaspaces 32 above the diaphragms 16, and the remainder of the, liquid passes into the working chamber of the coupling via the ports 39 in the casing 5. There is a continuous but restricted flo'w of working liquid from the spaces '32 through the leak-off nozzles 19 to the reservoir chamber 33. Again limiting the description to one valve 6 (which will be assumed-to beat the top of the working chamber although in fact it will of course rotate with the impeller) in normal full'speed operation of the coupling the pressure on the lower surface of the diaphragm 16 duev to the centrifugal weight of liquid on the relatively in the pressures acting on the upper and lower sides of the diaphragm 16 the latter is maintained in contact with its annular valve seats.

it now the scoop tube 34 is withdrawn from the ring of liquid in the reservoir chamber 33, liquid ceases to be fed to the collector groove 38, and therefore to the feed tube 41, and liquid also ceases to be fed to the working chamber through'the ports 39. The working chamber accordingly begins to empty due to the fiow of liquid through the restricted port 36 and discharge openings 29 I to the reservoir chamber 33. The feed tube 41 also begins to empty due to the flow of liquid through th leak-off nozzle 19, so that the closing fo'r'ce acting on the upper surface ofthe diaphragm 16 falls, until it becomes less than the opening force acting on the lower surface. At this moment the diaphragm 16 lifts'from its seats, thereby putting the working chamber in substantially unrestricted communication with the. reservoir chamber33 via the bore 8, space 28 and the discharge openings 29. Accordingly the working chamber empties rapidly. The time between the withdrawal of the scoop tube 34 and the lifting of the diaphragm 16 "from its seats maybe for example one or two seconds, when the coupling is rotating at normal full speed.

The spring 27 of one of the centrifugal control nozzles say the left-hand nozzle 21 in Fig. 1, has a strength such that at a predetermined coupling speed, say three quarters of full speed, the ball 26 of the said nozzle is moved from its seat by the spring 27. If the coupling is working at this speed, the. centrifugal force on the liquid in the feed tube 41 is less-than at full coupling speed, and the rate of leakage of liquid through the leak-off nozzle 19 is lower than at full coupling speed. If therefore the said centrifugal control nozzle 21 were not open, upon withdrawal of the scoop tube 41 a longer time would be required for the force acting above the diaphragm 16-to fall we value at whichthe diaphragm opens. The left-hand control nozzle 21 being open, however, the flow area for the discharge of liquid from the space "32 is increased since liquid. can now leak oif not only through the leak-01f nozzle 19 but also through the discharge por'ts25 of the left-hand control nozzle 21. By selecting suitable dimensions for this nozzle 21. it can be arranged that when the scoop tube 34 is with drawnthe time that elapses between the withdrawal of the scoop tube and the: lifting of the diaphragm from its seats is substantially the same at the lower coupling speed as at thefull coupling speed. 7 I

The spring27 of the other (right-hand) centrifugal control nozzle 21 has a force such that this nozzle opens at a predeterminedstill lower coupling speed, e.g., onehalf full speed, so that at this speed the flow area for the flow of liquid from the space 32 is further increased in that liquid can alsofflowthrough the discharge ports 25 oftheright hand control nozzle 21. When the scoop tube-34 is withdrawn 'at this still lower coupling speed the time that elapses before the diaphragm 16 lifts is substantially the same as at full speed and at the first-mentioned lower speed.

By employing one or more centrifugal control nozzles having springs of different strengths as above described the time lag between the withdrawal of the scoop tube 34 and the lifting of the diaphragm valve 16 can be made substantially the same for diiferent operating speeds, and the greater the number of such control valves 21 associated with each diaphragm valve 6, the greater is the number of coupling speeds for which the said time lag is substantially the same.

If desired, each feed tube 41 may be arranged to feed working liquid to a plurality of diaphragm valves 6 conveniently arranged closely adjacent one another, or a feed tube 41 may be associated with each diaphragm valve 6 and the spaces 32 outside the diaphgram 16 of a group of valves 6 can be connected together by pressure equalising tubes so that one group of control nozzles 21 will serve to control the said groups of valves.

In a modification of the above described arrangement instead of using control nozzles 21 of a type that are either fully closed or fully open according to the coupling speed, there may be associated with each diaphragm valve 6 or with one or more groups of diaphragm valves a centrifugal control valve which opens progressively in response to decreasing speed of the coupling, whereby to increase progressively the flow area available for the flow of liquid from the space 32 and thereby enable a substantially constant short time lag to be obtained over a range of coupling speeds.

In a further modification the said centrifugal control nozzle may be thermostatically regulated so that the flow area decreases with increased temperature of the working liquid.

The invention is not limited to turbo couplings of the scoop control type herein described. It may be applied for example to turbo couplings in which working liquid is supplied to the working chamber by a pump, from a sump in which the working liquid from the working chamber collects. Alternatively the coupling may be suppplied from an elevated tank to which the working liquid is supplied by a pump drawing from the said sump. In these latter arrangements a control valve is provided whereby working liquid may be admitted to the coupling inlet duct leading to the said passage to control also the operation of the said diaphragm quick-emptying valves. In another arrangement a control valve may directly control the liquid admitted to said passage.

I claim:

1. A hydraulic turbo coupling comprising, rotary vaned impeller and runner elements within a rotary work ing chamber formed by a rotary casing, at least one quickemptying valve rotatable with said casing, said valve comprising a valve element that controls an outlet port of the working chamber, said element being subjected on one side to the centrifugal pressure of the working liquid in the working chamber to open said valve, a duct communicating with the other side of said valve element and with a source of working liquid to close said valve. the liquid in said duct being subjected to centrifugal head when the turbo coupling is in operation, leak-0E means enabling liquid to leak off from the said other side of said valve element, means operable to reduce the supply of working liquid to said duct whereby to reduce the pressure on the said other side of said valve element to open said outlet port and rapidly empty said working chamber, and control means operable in response to a reduction in the angular speed of said quick-emptying valve to increase the rate at which pressure on the said other side of said valve element falls, when said lastmentioned means are operative in response to a reduction in the supply of liquid to said duct.

2. A hydraulic turbo coupling comprising, rotary vaned impeller and runner elements within a rotary working chamber formed by a rotary casing, at least one quickemptying valve rotatable with said casing, said valve comprising a valve element that controls an outlet port of the working chamber and which element is subjected on one side to the centrifugal pressure of the working liquid in the working chamber to open said valve, a duct communicating with the other side of said valye element and with a source of working liquid to close said valve,

, the liquid in said duct being subjected to centrifugal head when the turbo coupling is in operation, leak-0E means enabling liquid to leak oil from the said other side of said valve element, means operable to reduce the supply of working liquid to said duct whereby to reduce the pressure on the said other side of said valve element to open said outlet port and rapidly empty said working chamber, control means operable in response to a reduction in the angular speed of said quick-emptying valve to increase the eifective flow area of said leak-ofi means, whereby the pressure on the said other side of the valve element falls more rapidly, when said last-mentioned means are operative, in response to a reduction in the supply of liquid to said duct than it would do if said control means were not provided.

3. A hydraulic turbo coupling according to claim 1 wherein said quick-emptying valve includes at least one continuously open leak-oif nozzle via which liquid can flow away from the said other side of thevalve element, and said control means comprise at least one centrifugally-controlled valve with at least one discharge port, said centrifugally controlled valve being operative at and below a predetermined angular speed of said quickemptying valve, to open said discharge port.

4. A hydraulic turbo coupling according to claim 3, wherein said control means comprises a plurality of centrifugally controlled valves and discharge ports, said centrifugally controlled valves opening at and below diflerent predetermined angular speeds of said quick-emptying valve.

5. A hydraulic turbo coupling according to claim 1, wherein a plurality of quick-emptying valves are provided and at least some of them are supplied with working liquid through a common duct.

References Cited in the file of this patent UNITED STATES PATENTS 2,186,956 Canaan Jan. 16, 1940 2,256,878 Black Sept. 23, 1941 2,423,812 Karl et a1. July 8, 1947