Scoop-controlled fluid couplings

• US 4,671,061 A
• Filed: 04/26/1985
• Issued: 06/09/1987
• Est. Priority Date: 06/22/1982
• Status: Expired due to Fees

• Current Assignee: Fluidrive Engineering Company Limited
• Original Assignee: Fluidrive Engineering Company Limited
• Inventors: Elderton, John
• Primary Examiner(s): CHAMBERS, A MICHAEL
• Application Number:
  US06/726,955
• Time in Patent Office: 774 Days
• Field of Search: 60/337, 60/338, 60/347, 60/351, 60/367, 60/364, 416/180, 416/181, 416/203, 29/156.8 FC, 188/296
• US Class Current: 60/351
• CPC Class Codes: F16D 33/14 consisting of shiftable or adjustable scoops

Abstract

A scoop controlled fluid coupling has a toroidal working circuit W defined by vaned impeller and runner elements 11,12. Working liquid is supplied to the working circuit W from a rotating reservoir 9 by an adjustable scoop tube 15 having a scooping orifice 16, the radial position of which is to determine the degree of filling of the circuit W. To counteract unintentional changes in the filling due to thermal expansion of the liquid, the runner diameter is about 10% smaller than that of the impeller, and the runner has two sets of holes 54,55 which permit liquid to escape from the circuit.

Claims

1. In a scoop-controlled fluid coupling which includes:

an impeller and a runner which are supported coaxially with respect to and for independent rotation about a coupling axis, said impeller and runner each being a dished shell having plural angularly spaced vanes and together defining a working circuit for a working liquid;

an impeller casing supported on said impeller for rotation therewith;

a reservoir casing rotatable with said impeller for holding a quantity of the working liquid radially outside said working circuit; and

means which includes a radially movable scoop having a scooping tip adjustable to different radial positions in said reservoir casing for collecting liquid from a rotating ring of the liquid held in said reservoir casing and for supplying it to said working circuit, from which the working liquid can return to said reservoir casing through a restricted outlet;

the improvement comprising the outer profile diameter of said runner being from 5 to 15% smaller than the outer profile diameter of said impeller and the radially outermost part of said impeller lying radially beyond said runner, said impeller casing extending around said runner and projecting inwardly so as to radially overlap the exterior side of the runner to define a fluid-flow space therebetween, said fluid-flow space communicating with the radially outermost part of the impeller, said runner having first and second sets of holes provided through said shell thereof for direct communication with said fluid-flow space, the centres of said holes of said first set being spaced from said coupling axis by a distance in the range of 53 to 63% of the outer profile radius of said runner, and the centres of said holes of said second set being spaced from said coupling axis by a distance in the range of 65 to 75% of the outer profile radius of said runner, said holes in said runner communicating with said radially outermost part of said impeller through said fluid-flow space so that working fluid can flow from the working circuit through the holes and through the fluid-flow space and can communicate with the working circut through the radially outermost part of the impeller.

2. A fluid coupling according to claim 1, wherein the outer profile diameter of said runner is 10 to 15% less than the outer profile diameter of said impeller.

3. A fluid coupling according to claim 1, wherein the centres of said holes of said first and second sets of holes are spaced from said coupling axis by a distance which is in the range of 58% to 70% of the outer profile radius of said runner.

4. A fluid coupling according to claim 1, wherein the region between each adjacent pair of said angularly spaced vanes of said runner is an intervane pocket, said holes of said first and second sets each being provided in a respective said intervane pocket, said intervane pockets having said holes of said first set alternating with said intervane pockets having said holes of said second set.

5. A fluid coupling according to claim 4, wherein some of said intervane pockets of said runner, viewed in section planes which contain said coupling axis, have shapes which differ from the shapes of other said intervane pockets of said runner, and wherein said runner has core guide means on said vanes thereof and intervane passages in the region between said core guide means and said dished shell of said runner, some of said intervane passages, viewed in said section planes, having shapes which differ from the shapes of other said intervane passages.

6. A fluid coupling according to claim 2, wherein said runner has core guide means therein which, when viewed in different planes containing said coupling axis, has different dimensions;

wherein the region between each adjacent pair of said angularly spaced vanes of said runner is an intervane pocket;

wherein said holes of said first and second sets are each provided in a respective said intervane pocket, said intervane pockets having said holes of said first set alternating with said intervane pockets having said holes of said second set; and

wherein said holes of said first and second sets each have a diameter which is in the range of approximately 1% to 1.6% of the outer profile diameter of said runner.

7. A fluid coupling according to claim 1, including a cooler, and wherein said means for collecting liquid from said reservoir casing passes the collected liquid through said cooler and then discharges the collected liquid into said working circuit.

8. A fluid coupling, comprising coaxially supported impeller and runner elements which are independently rotatable about a coupling axis, each said element being in the form of a dished shell having vanes and said elements together defining a working circuit for a working liquid, an impeller casing supported on said impeller element for rotation therewith and extending around said runner element so as to define a fluid-flow space between said impeller casing and the exterior surface of said runner element, a reservoir for holding working liquid at a location outside said working circuit, leak-off means for defining a restricted flow path from said working circuit to said reservoir, and means for controlling the volume of liquid in said reservoir and for collecting surplus liquid from said reservoir and supplying said surplus liquid to said working circuit, wherein the outer profile diameter of said runner element is from 5 to 15% less than the outer profile diameter of said impeller element, the radially outermost part of said shell of said impeller element lies radially beyond said runner element, said runner element has angularly spaced holes through its shell in the region thereof having the greatest axial width, said holes communicating directly with said space, and said radially outermost part of said impeller element communicating through said space with said holes in said runner element so that working fluid which flows from the working circuit through the holes then flows through the space and can communicate with the working circuit through the radially outermost part of the impeller element.

9. A fluid coupling according to claim 8, including a cooler, and wherein said means for collecting liquid from said reservoir casing causes the collected liquid to pass through said cooler and then discharges the collected liquid into said working circuit.

10. A fluid coupling according to claim 8, wherein said holes extend through the shell of the runner element at a location relative to the coupling axis which is spaced radially inwardly a substantial distance from the outermost part of said impeller element.

11. A fluid coupling according to claim 10, wherein the location of said holes in said runner element is spaced from the coupling axis by a distance of no more than 75% of the outer profile diameter of said runner element.

12. A fluid coupling according to claim 11, wherein said runner element has first and second sets of angularly spaced said holes extending through the dish thereof for direct communication with said space, said first and second sets of said holes being radially spaced apart relative to said coupling axis.

13. A fluid coupling according to claim 12, wherein said first set of holes is spaced from the coupling axis by a distance in the range of 53 to 63% of the outer profile radius of said runner element and the second set of holes is spaced from the coupling axis by a distance in the range of 65 to 75% of the outer profile radius of the runner element.

14. A fluid coupling according to claim 8, wherein the region between each adjacent pair of angularly spaced vanes defines a pocket which directly communicates with no more than one of said holes.

15. In a scoop-controlled fluid coupling which includes:

an impeller and a runner which are supported coaxially with respect to and for independent rotation about a coupling axis, said impeller and runner each being a dished shell having plural angularly spaced vanes and together defining a working circuit for a working liquid;

an impeller casing supported on said impeller for rotation therewith;

a reservoir casing rotatable with said impeller for holding a quantity of the working liquid radially outside said working circuit; and

means which includes a radially movable scoop having a scooping tip adjustable to different radial positions in said reservoir casing for collecting liquid from a rotating ring of the liquid held in said reservoir casing and for supplying it to said working circuit, from which the working liquid can return to said reservoir casing through a restricted outlet;

the improvement comprising means for preventing any significant increase in the torque transmitted during prolonged acceleration of the coupling due to thermal expansion of the working liquid, said means including the outer profile diameter of said runner being from 5 to 15% smaller than the outer profile diameter of said impeller and the radially outermost part of said impeller lying radially beyond said runner, said impeller casing extending around said runner and projecting inwardly so as to radially overlap the exterior side of the runner to define a space therebetween, said space communicating with the radially outermost part of the impeller, said runner having first and second sets of holes provided through said shell thereof for direct communication with said space, the centres of said holes of said first set being spaced from said coupling axis by a distance in the range of 53 to 63% of the outer profile radius of said runner, and the centres of said holes of said second set being spaced from said coupling axis by a distance in the range of 65 to 75% of the outer profile radius of said runner, said holes in said runner communicating with said radially outermost part of said impeller through said space as provided between said impeller casing and said runner.

16. A fluid coupling according to claim 15, wherein each adjacent pair of angularly spaced vanes of said runner define a pocket therebetween, each said pocket being in direct communication with at least one of the holes of only one of said first and second sets.