US2992534A - Hydraulic turbo couplings - Google Patents

Description

July 18, 1961 H. SINCLAIR 2,992,534

HYDRAULIC TURBO COUPLINGS Filed Nov. 27, 1956 M VE/VTOQ Hapold Sinclaz'z ilnite This invention relates to hydraulic turbo couplings of the type comprising vaned impeller and runner elements, one of the said elements being rotatable together with a casing that extends over the back of the other element. The primary portion or impeller may be either the outer vaned element, i.e., the element that rotates with the casing, in which case the secondary portion or runner is the inner element which is light, i.e., of relatively low inertia, or on the other hand the impeller may the light inner elements in which case the runner is the outer element which together with the aforesaid casing is heavy, i.e., has relatively high inertia.

The invention relates particularly but not exclusively to hydraulic turbo couplings of the aforesaid type wherein a scoop tube, that may be fixed or adjustable, operates Within a casing that is rotatable with one or other of the said vaned elements and is used to transfer liquid from the said casing, which may be the casing mentioned in the previous paragraph or may be an additional casing.

There are advantages in using the vaned element as sociated with the casing as the impeller; notably when the turbo coupling is of the type that can be used for reduced speed drive with the working circuit in the partially empty condition and with correspondingly lower centrifugal pressure therein, which results in a slower rate of emptying through leak-off nozzles or quick emptying valves mounted in the casing.

It is good practice, when using hydraulic turbo couplings in conjunction with internal combustion engines, to mount the heavy impeller and casing directly on the engine crankshaft, through the intermediary of a diaphragm plate, which connects the crankshaft flange to the impeller. The said diaphragm plate affords a torsionally stiff connection that enables the high inertia of the impeller and casing to be accepted by the engine manufacturer even when the impeller carries, in addition to the above-mentioned casing that extends over the back of the runner, a rotatable reservoir chamber that serves to receive working liquid from the working circuit of the coupling and in which there is disposed an adjustable scoop tube that returns working liquid from the reservoir to the working circuit and serves as a means controlling the degree of filling of the working circuit. In turbo couplings of this type the runner is mounted on an output shaft carried by a pair of bearings spaced apart and housed in the impeller hub and in the casing that encloses the runner; hence, the axis of rotation of the impeller and the runner elements are coincidental.

With the upward trend in horse power and speed, and number of engine cylinders with increased length of engine crankshaft, the above described arrangement has been found unsuitable in some cases due to the weight of the impeller and the parts rotatable with it causing undue deflection of the engine crankshaft, and consequently the impeller has been provided with an extension shaft, supported in an outboard bearing through which shaft the engine is coupled to the impeller. This method, however, involved additional cost and increases the overall length of the installation, and usually introduces a more diflicult torsional vibration problem due to the resilience of the extension shaft.

It is the practice in marine diesel engine applications tates Patent a lot:

of the Vulcan gear wherein the hydraulic turbo coupling is incorporated within the casing of the reduction gearing, to connect the primary portion of the turbo coupling to the engine crankshaft by an intermediate shaft supported in a bearing in the gear case, and in many cases the primary portion or impeller must comprise the lighter inner element for the reason that considerations of the permissible torsional vibrations in the engine and impeller system do not permit the heavier element to be driven by the said intermediate shaft.

The object of the present invention is to provide a hydraulic turbo coupling of the foregoing type, either with or without a scoop tube, which when used in association with an internal combustion engine overcomes the above-mentioned difficulties.

In accordance with the invention the primary member of a hydraulic turbo coupling which includes an impeller and a rotatable casing that extends over the back of the secondary member or runner is provided with a spigot bearing for supporting part weight of the secondary member for rotation Within the primary member, and a further bearing supporting part weight of the primary member through a sleeve member that surrounds the output shaft and is provided together with a fixed housing for supporting the said further bearing, and a radial clearance is present around said output shaft within said sleeve member, said radial clearance being not less than 4 of the shaft diameter measured in the region where the greatest clearance is required around said shaft to permit of the axes of rotation of the primary and secondary members to be non-coincident.

In order that the invention may be clearly understood and readily carried into effect it will now be described in more detail with reference to the accompanying drawing, the single figure of which is a view in longitudinal section of a turbo coupling embodying the invention.

Referring to the drawing, the runner 1 is located adjacent the input side of the coupling and the impeller 2 is located towards the output side. The impeller 2 has connected to it a driving casing 3 that extends over the back of the runner l and is provided with a central boss or hub 4 (lower part of the figure) having a flange 5 to which the flange 6 of a diesel engine crankshaft can be bolted, so that effectively the said crankshaft is rigidly connected to the impeller 2. The runner 1 is formed with a central boss 7 that is bolted to a flange 8 on an output shaft 9, the inner end of shaft 9 being journalled in a spigot bearing 10 within the boss 4 of the casing 3. The outer end of the output shaft 9 is provided with a flange 11 for connection through a semi-flexible coupling, viz: one that permits of angular misalignment of the shafts to the member 12 mounted on the driven shaft. The impeller 2 is formed with a central boss 13 which is rigidly bolted to a flange 14 on a sleeve member 15 that surrounds the output shaft 9, and the outer end of the sleeve member 15 is supported in a bearing 16 Within a scoop tube manifold 17 mounted on a fixed bracket 17a, which is stationary but which may be adjusted in lateral position and in height to determine the position of the bearing 16 relative to the engine seating.

The coupling is provided with a cylindrical reservoir 18 one end of which is bolted to a flanged connection 19 on the radially outer part of the driving casing 3, and the other end of the reservoir 18 is formed by an end plate 20 with a large central orifice the inner periphery of which runs with suitable clearance within the scoop tube manifold 17, the central part of the plate 2.0 and the manifold being shaped to form labyrinths to prevent. the egress of liquid. The manifold 17 carries a scoop tube 21, with ascooping tip 21a, slidable in guides within a housing 22, which scoop tube, as is well known in the art, trans- 2,992,534. a a V f fers liquid from the rotating casing 18 through ducts (not shown) in the scoop housing 22 to an external cooler from which the liquid returns via ducts 2a to the working chamber formed between the vaned elements 1 and 2. The said scoop tube tip 21a is capable of movement towards and away from the periphery of the reservoir 18 by means of a control lever 23 carried by a control pin 24 that projects through the manifold 17 and scoop housing 22 and is drivably coupled to the scoop tube through the lever 24a.

The casing 3 is provided with spring loaded centrifugally operated valves, one of which is shown at 25, incorporating leak-oft nozzles 25a through which, during operation of the coupling, working liquid flows from the working chamber to the reservoir 18, where it is picked up by the scoop tube, circulated through an oil cooler, and transferred back to the working circuit.

With the arrangement described, part of the overhanging weight of the primary member 2 and part weight of the secondary member 1 is taken by the stationary bracket 17a, which is set in true lateral alignment with effective bearing 16 of the sleeve member 13 to be very slightly higher than the centre line of the crankshaft of the engine.

In this manner the properties of the Weight of the primary and secondary members carried by the bearing 16 can be adjusted to reduce the crankshaft deflection to an acceptably low figure.

Under the foregoing operating conditions the axis of rotation of the primary members cannot be coincident with the axis of rotation of the secondary members, and hence an adequate running clearance must be provided around the output shaft 9, the said clearance measured radially Within the sleeve member 15 being not less than $3 of the diameter of the output shaft 9 in the region where the greatest running clearance is required around said shaft.

In order to restrain passage of liquid from within the working chamber of the turbo coupling through the clear ance space 9a around the output shaft 9, particularly under conditions of internal pressure resulting from high torque and slip and also from rapid transfer of liquid into said working chamber, an annular chamber 26 adjacent the output shaft 9 is formed by the provision of a cylindrical member 27 one end of which is fixed to the wall of the impeller boss 13, this member 27 being concentric with and spaced radially from the output shaft and projecting partly over the flange 8 of the output shaft 9 into a recess 28 formed in the boss 7 of the runner 1. There is thus provided a labyrinth that restricts the entry of working liquid under local pressure into the chamber 26. To restrict the passage of liquid out of the chamber 26 there is provided a second labyrinth seal in the form of an annular member 29 of L-section bolted to the runner boss 7 with a cylindrical portion extending parallel to the runner shaft and projecting into an annular groove 30 in the impeller boss, being spaced radially within the cylindrical member 27. There is thus formed a second labyrinth the purpose of which is to trap Within the chamber 26 liquid that has passed the first-described labyrinth. A plurality of radially extending tubes 31 are provided, spaced regularly around the axis of the coupling, each tube 31 (only one of which is shown) communicating at its radially inner end with the interior of the chamber 26, and the radially outer end of each tube 31 projecting through the impeller shell and flange and so being in open communication with the reservoir 18. With this arrangement, working liquid that is trapped in the chamber 26 is expelled therefrom and directed into the reservoir 18 under the action of the centrifugal pressure exerted on liquid in the tubes 31 when the impeller 2 is rotating. A further drain to return to the reservoir any liquid passing through the clearance space around the output shaft 9 may be provided in the sleeve member at 15b near the outer end of the said shaft; and a further labyrinth seal 32 may be arranged at the outer end of the 4 a shaft 9 within the stationary mounting 17 to direct any liquid reaching that point into a drain duct 33 leading to a sump tank 34 supporting the said bracket 17. The sump tank 34 may be arranged to be continuously evacuated, when the coupling is running, by an ejector operated by the pressure created in the scoop tube and discharging back into the reservoir 18.

In accordance with a further aspect of the present in vention there is therefore provided a hydraulic turbo coupling having vaned impeller and runner elements, one of the said elements being provided with a shaft that passes with a working clearance through a sleeve member connected for rotation with the other element and supported by a fixed external bearing, and wherein there is provided an intercepting chamber with at least one seal that restricts the flow of liquid therethrough situated between the working chamber and the clearance space between said shaft and sleeve member, the said intercepting chamber being provided with at least one duct through which liquid is ejected with the aid of centrifugal force when the turbo coupling is in operation. The said duct may for example extend from said chamber to the outer profile diameter of the working circuit, or beyond.

An additional step that may be employed to restrain the leakage of working fluid along the clearance space is to taper the bore of the sleeve member 15 as shown, the bore being widest at the end adjacent the impeller 2 so that when the coupling is running centrifugal force tends to prevent Liquid from flowing to the outer end of the sleeve member 15. In this case the output shaft 9 is preferably also correspondingly tapered, as shown.

Evidently the present invention is not limited to hydraulic turbo couplings of the scoop control type provided with leak-off nozzles, e.g., couplings of the kind illustrated in British patent specification No. 493,703, in which the more the scoop tube orifice is extended the more liquid is transferred from the reservoir chamber to the working circuit. It can also be applied to couplings of the scoop trimming type provided with a filling pump or other source of pressure, and in which there is substantially free communication between the working circuit and a scoop tube chamber, so that increased extension of the scoop tube orifice results in a reduced filling of the working circuit; see for example British patent specification No. 719,470. The invention may further be applied to turbo couplings in which a fixed scoop tube is provided for transferring liquid from the working chamber through an external cooler and thence back to the Working chamber, see for example, British patent specification No. 328,028. The invention may be yet further applied to turbo couplings in which means other than a scoop tube are employed for varying the filling of the working circuit, e.g., a Vulcan hydraulic coupling with a pump; see, for example, British patent specification No. 230,412.

In the above-described specific embodiment of the invention it is envisaged that the sump tank 34 that supports the scoop tube manifold 17 (which in turn supports the bearing 16 for the sleeve member 15 of the impeller) will be of rigid construction and will be mounted on the same heavy seating as the engine, so that the requisite conditions of alignment can be maintained. In a modification of this arrangement the manifold 17 and bearing 16 may be supported by a rigid structure, e.g., a bell housing solidly bolted to the prime mover and thus independent of the engine seating.

The prime mover will generally be a diesel engine to the crankshaft of which the turbo coupling is rigidly connected as described above, but evidently a turbo coupling according to the invention may be used with a diesel englue or other engine or other types of 'prime movers, with appropriate modification if necessary of the connection of the part of the coupling that is driven by the prime mover. For example, an engine or an electric motor having an adequately stiff driving shaft may be connected to the coupling through the medium of a diaphragm driving plate, as is standard practice with electric motor drives to turbo couplings of the above-mentioned scoop control type. In the upper half of the figure the coupling is shown as provided with such a driving plate 34.

I claim:

1. A hydraulic turbo coupling comprising a primary part including a vaned impeller and a secondary part including a vaned runner, said primary part also including a casing rotatable with said impeller and extending over the back of said runner and having a central hub, said impeller and said casing together forming a substantially closed working chamber, and said impeller and said runner together defining a toroidal working circuit wherein in the normal operation of the coupling a rotating vortex ring of working liquid is established, a sleeve fast with said impeller and projecting therefrom away from said working circuit, an output shaft fast with said runner and projecting through said impeller and projecting also through said sleeve with a radial clearance, a bearing for said shaft within the hub of said casing, said bearing being of a type that permits relative angular movement of the axes of said impeller and runner by virtue of said radial clearance, a bearing for said sleeve at the end thereof remote from said impeller, an adjustable stationary support for said last mentioned bearing, and torsionally rigid means for drivably connecting the output element of a prime mover to said casing.

2. A hydraulic turbo coupling comprising a primary part including a vaned impeller and a secondary part including a vaned runner said primary part also including a casing rotatable with said impeller and extending over the back of said runner and having a central hub, said impeller and casing together forming a substantially closed working chamber, and said impeller and said runner together defining a toroidal working circuit wherein in the normal operation of the coupling a rotating vortex ring of working liquid is established, a sleeve fast with said impeller and projecting therefrom away from said working circuit, an output shaft fast with said runner and projecting through said impeller and projecting also through said sleeve with a radial clearance, a bearing for said shaft within the hub of said casing, said bearing being of a type that permits relative angular movement of the axes of said impeller and runner by virtue of said radial clearance, a bearing for said sleeve at the end thereof remote from said impeller, an adjustable stationary support for said last-mentioned bearing, said primary part also including a reservoir rotatable with said impeller, and means for rigidly and drivably connecting the output element of a prime mover to said casing.

3. A hydraulic turbo coupling according to claim 2, including means whereby in the operation of the coupling working liquid flows continuously from said working chamber to an external circuit including said reservoir and further means for continuously returning liquid from said external circuit to said working chamber via at least one port in the shell of said impeller.

4. A hydraulic turbo coupling comprising a primary part including a vaned impeller and a secondary part including a vaned runner positioned relative to said impeller to provide an annular space between them, said primary part also including a casing rotatable with said impeller and extending over the back of said runner and having a central hub, said impeller and said casing together forming a substantially closed working chamber, and said impeller and said runner together defining a toroidal working circuit wherein in the normal operation of the coupling a rotating vortex ring of working liquid is established, a sleeve fast with said impeller and projecting therefrom away from said Working circuit, an output shaft fast with said runner and projecting through said impeller and projecting also through said sleeve with a radial clearance, a bearing for said shaft within the hub of said casing, said bearing being of a type that permits relative angular movement of the axes of said impeller for said sleeve at the end thereof remote from said impeller, an adjustable stationary support for said last-mentioned bearing, and means for rigidly and drivably connecting the output element of a prime mover to said casing, means defining a liquid intercepting chamber between said working circuit and said clearance space, said intercepting chamber having restricted communication at the inner profile diameter of said working circuit with said annular space, and at least one duct rotatable with said impeller and communicating with said intercepting chamber, and serving to eject liquid from said intercepting chamber with the aid of centrifugal force when said impeller is rotating.

5. A hydraulic turbo coupling comprising a primary part including a vaned impeller and a secondary part including a vaned runner positioned relative to said impeller to provide an annular space between them, said primary part including a casing rotatable with said impeller and extending over the back of said runner and having a central hub, said impeller and said casing together forming a substantially closed working chamber, and said impeller and said runner together defining a toroidal working circuit wherein in the normal operation of the coupling a rotating vortex ring of working liquid is established, a sleeve fast with said impeller and projecting therefrom away from said working circuit, an output shaft fast with said runner and projecting through said impeller and projecting also through said sleeve with a radial clearance, a bearing for said shaft within the hub of said casing, said bearing being of a type that permits relative angular movement of the axes of said impeller and runner by virtue of said radial clearance, a bearing for said sleeve at the end thereof remote from said impeller, an adjustable stationary support for said last-mentioned bearing, said primary part also including a reservoir rotatable with said impeller, and means for rigidly and drivably connecting the output element of a prime mover to said casing, means defining a liquid intercepting chamber between said working circuit and said clearance space, said intercepting chamber having restricted communication at the inner profile diameter of said working circuit with said annular space, andat least one duct rotatable with said impeller and communicating with said intercepting chamber, and serving to eject liquid from said intercepting chamber to said reservoir with the aid of centrifugal force when said impeller is rotating.

6. A hydraulic turbo coupling comprising a primary part including a vaned impeller and a secondary part including -a vaned runner, said primary part also including a casing rotatable with said impeller and extending over the back of said runner and haw'ng a central hub, said impeller and said casing together forming a substantially closed working chamber, and said impeller and said runner together defining a toroidal working circuit wherein in the normal operation of the coupling a rotating vortex ring of working liquid is established, a sleeve fast with said impeller and projecting therefrom away from said working circuit,- an output shaft fast with said runner and projecting through said impeller and projecting also through said sleeve with a radial clearance, a bearing for said shaft within the hub of said casing, said bearing being of a type that permits relaitve angular movement of the axes of said impeller and runner by virtue of said radial clearance, a bearing for said sleeve at the end there of remote from said impeller, an adjustable stationary support for said last-mentioned bearing, and means for rigidly and drivably connecting the output element of a prime mover to said casing, said radial clearance being not less than of the diameter of said output shaft measured in the region Where the greatest clearance is required around said output shaft to permit of relative angular adjustment of the axes of said impeller and runner.

7. A hydraulic turbo coupling comprising a primary and runner by virtue of said radial clearance, a bearing part including a vaned impeller and a secondary part including a vaned runner, said primary part also including a casing rotatable with said impeller and extending over the back of said runner and having a central hub, said impeller and said casing together forming a substantially closed Working chamber, and said impeller and said runner together defining a toroidal working circuit wherein in the normal operation of the coupling a rotating vortex ring of Working liquid is established, a sleeve fast With said impeller and projecting therefrom away from said working circuit, an output shaft fast with said runner and projecting through said impeller and projecting also through said sleeve with a radial clearance, a bearing for said shaft Within the hub of said casing, said bearing being of a type that permits relative angular movement of the axes of said impeller and runner by virtue of said radial clearance, a bearing for said sleeve at the end thereof remote from said impeller, an adjustable stationary support forsaid last-mentioned bearing, said primary part also including a reservoir rotatable with said impeller, and means for rigidly and drivably connecting the output element of a prime mover to said casing, said radial clearance being not less than of the diameter of said output shaft measured in the region where the greatest clearance is required around said output shaft to permit of relative angular adjustment of the axes of said impeller and runner.

References Cited in the file of this patent UNITED STATES PATENTS 2,187,667 Sinclair et a1. Jan. 16, 1940 2,212,901 Schneider Aug. 27, 1940 2,264,340 Sinclair Dec. 2, 1941 2,271,919 Jandasek Feb. 3, 1942 2,281,161 Kuhns et a1 Apr. 28, 1942 2,379,015 Lysholm June 26, 1945 2,649,689 Oding Aug. Q5, 1953 2,784,555 Anderson Mar. 12, 1957

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