US3150276A

US3150276A - Fluid-cooled machines

Info

Publication number: US3150276A
Application number: US82571A
Authority: US
Inventors: William H Moyer
Original assignee: Eaton Manufacturing Co
Current assignee: Eaton Corp
Priority date: 1961-01-13
Filing date: 1961-01-13
Publication date: 1964-09-22
Anticipated expiration: 1981-09-22
Also published as: GB916960A; ES269780A1

Description

2 Sheets-Sheet 1 IIS Sept. 22, 1964 w. H. MOYER FLUID-COOLED MACHINES Filed Jan. 15, 1961 Sept. 22, 1964 w. H. MOYER FLUID-COOLED MACHINES 2 Sheets-Sheet 2 Filed Jan. 13, 1961 United States Patent 3,150,276 FLUID-COOLED MACHINES William H. Meyer, Kenosha, Wis., assignor to Eaton Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Filed Jan. 13, 1961, Ser. No. 82,571 15 Claims. (Cl. 310-54) This invention relates to fluid-cooled machines, and with regard to certain more specific features, to liquidcooled electrical machines such as eddy-current couplings and the like.

Among the several objects of the invention may be noted the provision of liquid-cooled electrical machines in which the path of coolant is controlled to bring about highly effective cooling of a heated rotor such as, for example and more particularly, an eddy-current drum of an eddy-current electric coupling; the provision of couplings of this class which will bring about effective liquid cooling of the exterior of the rotor Without excessive hydraulic drag and so-called slugging effects of the coolant; and the provision of couplings of this class in which by efficient use of the coolant its required volume is minimized. Other objects and features will be in part apparent and in part pointed out hereinafter.

Theinvention accordingly comprises the construction hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated.

FIG. 1 is an axial section, parts being in elevation, illustrating the invention as applied by way of example to an eddy-current coupling;

FIG. 2 is a developed plan View on a reduced scale of the drum of the coupling, with coolant deflector means superimposed thereover; r

FIG. 3 is a left end view in elevation of the deflector means; and

FIGS. 4-3 are enlarged sections taken on lines 4-4 through s -s, respectively, on FIGS. 2 and 3.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawmgs.

As used hereinafter, the term coolant includes any appropriate liquid adapted to absorb heat, water being the conventional liquid for the purpose.

There are various types of electrical machines employing rotors which become heated under load such as, for example, inductor drums of eddy-current couplings and the like. Sometimes these machines are constructed with their field poles inside the inductor drums. In such event, various cooling schemes have been employed, as for example, spraying water on the outside of the drum or introducing it in the magnetic gap between the poles and the inside of the drum. Introduction of a limited amount of coolant into the gap is satisfactory, but introduction of a large amount of water therein causes parasitic drag and erratic action, which interfere with smooth control of speed and loads.

A difficulty connected with spraying water directly on the outside of a drum is that at any one point it is slung from the surface of the drum after remaining thereon for only a short interval and is then discharged. Thus the water temperature is raised only a few degrees, resulting in inefficient abstraction of heat from the drum.

3,150,276 Patented Sept.- 22, 1964 To correct this difficulty, axially disposed vanes have been employed to return the water to the drum to abstract additional heat, but this has again incurred the difficulty of slugging of the coolant, thereby incurring erratic action.

I By means of the present invention, substantial amounts of heat are abstracted by improving the path of the coolant exteriorly of the drum assembly for repeated contact therewith, so that the temperature of the coolant is raised a substantial amount with minimum drag and no slugging.

A basic type of coupling upon which the present invention is an improvement is shown in detail in Patent 2,855,527. A brief description of the same herein will suflice toexhibit the type of structure to which the present invention applies. I

Referring now more particularly to FIG. 1, there is shown at numeral 1 a water-tight casing consisting of a central housing 3, having end bells 5 and 7. End bell 5 supports a drive shaft 9, and 7 supports a driven shaft 11, carried in bearings 13. The member 5 may also be a part of an associated driving motor fragmentarily illustrated at M on FIG. 1.

Keyed at 17 to the drive shaft 9 is a spider 15. The spider supports a cylindrical eddy-current inductor drum assembly 19, composed of a term-magnetic material such as iron or steel. Cooling fins or ribs 75 are carried on its exterior but these may in some instances be omitted.

Keyed to the driven shaft 11 at key 21 is a magnetic field pole member 23. A pilot bearing 25 is located between drive shaft 9 and the field member 23. Closerunning sealing means 27 is provided between members 15 and 23 Without interposed packing. Member 23 carries a magnetic pole assembly 29, consisting of a ring 31 supported on the field member by a non-magnetic welded band 33. The members 23 and 31 carry interdigitated polar teeth or poles 35. Between these and the inside of drum assembly 19 is a magnetic gap G.

End bell 7 has bolted toit a stationary ring-shaped magnetic support 37 for an annular field coil 39. Electrical connections for exciting the field coil are shown at 41. Interdigitated labyrinth sealing rings 43 and 45 are attached to field member 23 and bell 7, respectively, these also having close-running fits without packing.

A tachometer type of generator 47, driven by shaft 11, supplies current for a line 49 and is suitably connected with the exciting circuit of coil 39 to control excitation in accordance with the speed of shaft 11. Electrical circuits for the purpose are known and require no description herein. It suffices to say that at a given speed control setting excitation of coil 39 increases with decrease in speed of the shaft 11 and vice versa, thus performing a speed-regulating function on shaft 11.

I When the field coil 39 is excited, a toroidal magnetic loop, a half section of which is arbitrarily diagrammed by the dotted line L, interlinks the field member and drum assembly 19. Upon relative rotation between

members

23 and 19, eddy currents are generated in the latter to produce a reactive magnetic field, which causes a magnetic drive with some slip between the field member 23 and the drum assembly 19. The eddy currents gen erate heat in the drum assembly 19. The drum assembly is thercfore required to be cooled. In order to abstract ployed.

The spider 15 is shaped at 57 and includes an inner attached ring or dam 51 so as to form a circular coolantreceiving trough 53 within the spider. The spider is arranged with an inner running seal 55 in connection with an annular boss 56 of a stationary annular diaphragm 58 forming part of the housing'3. The formation 57 also provides an outer running seal around the boss 56. The sealing means 55, 57 are of the freerunning type, having close running fits without packing. A water inlet 59 delivers water through the diaphragm 58 and boss 56 to the trough 53. It will be understood that more than one water inlet may here be provided, if

desired. a j The drum assembly or rotor is provided with peripheral radially disposed passage means comprising a plurality of nozzle inserts 61 placed around the outer flange of the spider 15. These provide an array of openings which communicate between the trough 53 and the outside of the drum assembly. The openings are arranged at an angle relative to the rotor axis or axis of rotation of the machine. A primary channel-shaped deflector is shown at 63. This is attached to the housing member 3 by any convenient fastening means such as, for example, metal screws 65; or it may be welded thereto or cast integrally therewith. The primary deflector 63 extends circularly around the drum assembly to subtend an angle A, which is shown in FIG. 3 to be, for example, 240. This leaves a blank space subtending an angle B of, for example, 120. The deflector 63'is of symmetrical bicorn shape, having two flaring

curved horns

63 and 63* extending from a central section 44. A symmetrically arranged secondary circular bicorn channel or deflector 67 is attached by suitable means such as welding to the primary deflector. Its horns are numbered 67 and 67 The secondary deflector 67 does not extend around the drum assembly as far as the primary deflector and is located adjacent the central portion of the primary deflector. It subtends an angle C of approximately 120. The exact values of angles A, B and C are not critical. As above-mentioned,

deflectors

63 and 67 may be built integrally if desired. 7 Referring to FIGS. 48, it will be seen that the bicorn deflector is multiple arched by means of the primary and

secondary deflectors

63 and 67, these being convex toward the drum assembly 19. These arches progressively change shape in the successive sections 44 to 6-6. The arch of channel 63 continues to change shape through sections 7- -7 to 8-8, as shown. The left-hand margin of channel 63 is angled relative to the rotor axis in generally (if not precisely) the same direction as the angles of the ports of the nozzle inserts 61, thus functioning as a scoop for coolant ejected from these ports.

In View of the above, it Will be seen that the lefthand horn of each deflector is a reverse form of its righthand horn. Thus the forms of the successive sections on the left side of the deflector correspond in shape sequence to the shape sequence on the right side. I FIGS. 4-8 show typical paths that the particles of coolant follow in the successive indicated right-hand deflector sections as the drum assembly is rotated clockwise, viewed from the left in FIG. 1. During such rotation, coolant particles in corresponding sections-of the left side of the deflector in FIG. 2 will have generally similar (although not identical) paths as particles in the indicated sections in the right side. Water, for example, is delivered from the inlet 59 through members 58 and 56 to trough 53, where it is momentarily centrifugally held and from which it is centrifugally forced out at an angle to the rotor axis through the openings in the nozzles 61. The water enters the primary deflector 63 in a skew direction of flow, being scooped and turned inward or reverted toward and against the drum assembly. The Water will then for a short interval be 4 in contact with the fins 75 on the drum assembly. It will then be thrown oil? by centrifugal force and will strike either the primary or the secondary deflector, depending upon the position of the water'particle along the length of the deflector. This process repeats, the water being repeatedly redirected or reverted toward the drum assembly. The curved darts in FIGS. 48 illustrate the axial progress of the coolant, but these darts are incapable of illustrating the skew progress, which is illustrated by the dotted darts on FIG. 2. Eventually, each particle will reach a point not under the area covered by the deflector and will be thrown by the drum assembly to the inside of the central housing, which is shaped so as to provide a path for the water to an outlet 69. The straight darts in FIGS. 48 illustrate this.

In order to prevent waste of water from the jets while traversing angle B, there is provided a circular shoe 71 (FIG. 1) of a length equal to the length of the are formed by angle B. A close-running fit is provided between the drum and the shoe so that the outlets of openings in the inserts 61 are substantially blocked when within the shoe. The shoe 71 may be omitted, if desired.

Openings '73 are provided in the spider 15. In the event of an emergency or unusual condition, wherein too much coolant is fed into the trough 53, there will occur a spill over the dam 51 and through the magnetic gap between thepoles 35 and drum assembly 19. Such overflow will finally be centrifugally ejected at the righthand margin of the drum assembly, from whence it is directed to the outlet 69. r 1 From the above it will be seen that one feature of the invention is that water is repeatedly returned by the

deflectors

63 and 67 to the fins 75 on drum 19 in multiple passes, during each one of which the water picks up additional heat. Thus a smaller amount of water may be used for a given cooling effect than heretofore inmachines employing a single-pass circulation means.

Another feature is that the return passes of Water to the drum assembly 19 are helically disposed, thus assuring that the entire surface of the drum assembly in all planes perpendicular to its axis of rotation will receive water. Thus the efliciency of cooling is raised, not only by reason of the multi-pass contact of the water with the drum assembly, but also by reason of the fact that the entire surface of the drum assembly is repeatedly contacted.

Another feature of the invention is that the open annular trough shapes of the deflector means provide for free annular movements of the coolant without inward projections such as would cause slugging. Thus there is a free rolling progress of the water, wherein there are both peripheral and axial components. The peripheral components allow a streamlined circular component of flow adapted to obviate the slugging action of the water. The axial components of the movement, which occur with a helically disposed inflow of water to the drum assembly, assure distribution across substantially the entire face of the drum assembly.

While the multi-pass deflector consisting of

components

63 and 67 is shown to comprise a primary arch form 63 and a secondary arch form 67, it will be understood that the primary arch form 63 may be used by itself, or more than one secondary arch form 67 may be used. Moreover, one or the other horn of the bicorn form may be used and some of the advantages of the invention obtained.

In view of the above, it will be seen'that the several objects of the invention are achieved and other advantageous results attained. a

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illlustrative and not in a limiting sense.

I claim:

1. A liquid-cooled electrical machine comprising a polar field member, an inductor drum surrounding said field member and spaced therefrom by a magnetic gap, a coolant deflector adjacent the outside of the peripheral wall of said drum, said deflector extending substantially around said drum, a rotatable member supporting. said drum at one end thereof, said rotatable member having a dam-forming trough on the inside thereof, means providing openings extending from the inside of said rotatable member from the trough to the outside of said drum, said trough being adapted to receive coolant when said rotatable member is rotated and deliver coolant centrifugally to said openings for movement therethrough toward said deflector, said deflector being adapted to revert coolant from said openings toward said drum, means for delivering coolant to said trough, and communicating means between the trough and around said dam adapted to carry any spill-over of coolant from 'the trough over the dam to said gap, said drum being open at its other end for escape of coolant from the gap.

2. A liquid-cooled machine comprising a hollow rotor subject to heating, said rotor having a peripheral array of coolant ports extending from inside to outside thereof, means adapted to introduce coolant within the rotor and to the ports for centrifugal ejection therefrom, channelshaped deflector means extending circularly part way around and with its concave inside surface toward the rotor and having one margin disposed with respect to said ports to receive centrifugally ejected coolant therefrom over an angle less than 360, the concave side of said deflector means being arched in an axial direction toward its other margin to deflect coolant back toward the rotor from said other margin, and circular port'covering means adjacent to and covering said ports throughout an angle constituting substantially the remainder of said 360.

3. A liquid-cooled machine according to claim 2, wherein said port-covering means is disposed exteriorly to the rotor at the outlets of said ports.

4 A liquid-cooled machine comprising a hollow rotor subject to heating, said rotor having a peripheral array of coolant ports extending from inside to outside thereof, means adapted to introduce coolant within the rotor and to the ports for centrifugal ejection therefrom, channelshaped deflector means of bicorn form extending around and with its convex side toward the rotor and having one margin disposed with respect to said ports to receive centrifugally ejected coolant therefrom, the concave inside of said deflector means being arched in an axial direction toward its other margin to deflect coolant back toward the rotor from said one margin, the arch form of the deflector means flaring in opposite directions along the two horns of said bicorn shape.

5. A liquid-cooled machine according to claim 4, wherein the bicorn shape of said deflector means is symmetrical with respect to a comparatively narrow central section.

6. A liquid-cooled machine comprising a hollow rotor subject to heating, said rotor having a peripheral array of coolant ports extending from inside to outside thereof, means adapted to introduce coolant within the rotor and to the ports for centrifugal ejection therefrom, channelshaped deflector means of bicorn form extending around and with its concave inside surface toward the rotor and having one margin disposed with respect to said ports to receive centrifugally ejected coolant therefrom, the concave inside of said deflector means being multiple arched in an axial direction toward its other margin to deflect coolant back toward the rotor from said one margin, at least one of the multiple arch forms of the deflector means flaring in opposite directions along the two horns of said bicorn shape.

7. A liquid-cooled machine according to claim 6,

. 6 wherein the bicorn shape of said deflector means is symmetrical with respect to a comparatively narrow central section.

8. A liquid-cooled machine comprising a hollow rotor subject to heating, said rotor having a peripheral array of coolant ports extending from inside to outside thereof, means adapted to introduce coolant within the rotor and to the ports for centrifugal ejection therefrom, channel.- shaped deflector means of bicorn form extending around and with its concave inside toward the rotor and having one margin disposed with respect to said ports to receive centrifugally ejected coolant therefrom, the deflector means being multiple arched in an axial direction toward its other margin to deflect coolant back toward the rotor from said one margin, one arch form of the deflector means flaring in opposite directions along the two horns of said bicorn shape and the other arch form having substantially parallel margins.

9. A liquid-cooled machine according to claim 8, wherein the bicorn shape of said one arch form is symmetrical with respect to a comparatively narrow central section and the other arch form comprises symmetrically arranged portions attached thereto.

10. A liquid-cooled machine comprising a hollow rotor subject to heating, said rotor having a peripheral array of coolant ports extending from the inside to the outside thereof, means adapted to introduce coolant within the rotor and to the ports for centrifugal ejection therefrom, channel-shaped deflector means extending around the rotor and having one margin disposed with respect to said ports to receive centrifugally ejected coolant therefrom, said channel-shaped deflector means being axially concavely arched toward the rotor, the arch having helical flares outward from a mid section in opposite peripheral directions.

11. A liquid-cooled machine according to claim 10, wherein the deflector means includes additional portions arched toward the rotor adjacent said flares.

12. A liquid-cooled machine comprising a substantially cylindrical hollow rotor subject to heating, internal peripheral groove means in said rotor, said rotor having a peripheral array of ports extending therethrough from said groove means, said ports being angled relative to the rotor axis, means adapted to introduce coolant within said groove means for delivery to said ports and centrifugal ejection therefrom, channel-shaped deflector means extending partially around and with its concave side toward the rotor and having one margin angled relatvie to the rotor axis in generally the same direction as the port angles to scoop centrifugally ejected coolant therefrom, the deflector means being arched in an axial direction toward toward its other margin to deflect coolant back to the rotor from said other margin, said other margin having at least one helical direction with respect to the rotor axis.

13. A liquid-cooled machine comprising a substantially cylindrical hollow rotor subject to heating, internal peripheral groove means in said rotor, said rotor having a peripheral array of axially angled ports extending therethrough from said groove means, means adapted to introduce coolant within said groove means for delivery to said ports and centrifugal ejection therefrom, channelshaped deflector means extending partially around and with its concave side toward the rotor and having one margin sloping in the same general direction as said angled ports to scoop centrifugally ejected coolant therefrom, the concave side of said deflector means being arched in an axial direction toward its other margin to deflect coolant back to the rotor from said other margin, said other margin having at least two different directions with respect to the rotor axis.

14. A liquid-cooled machine comprising a hollow rotor subject to heating, said rotor having a peripheral array of coolant ports extending from the inside to the outside thereof, means adapted to introduce coolant within the rotor and to the ports for centrifugal ejection therefrom,

7 8 channel-shaped deflector means extending around the rotor References Cited in the file of this patent and haifing one Inargin disposed with respect to said ports UNITED STATES P ATENTSV to rece1ve centrifugally JCtd coolant therefrom, said -channel-shaped deflector means being axially concavely 23871953 Wmther t June 1942 arched toward the rotor, the arch having at least one heli- 5 2,965,777. Jagschk? 20, 1960 'tion and a comparatively wide section.

cal flare extending between a comparatively narrow sec- FOREIGN PATENTS 15. A liquid-cooled machine according claim 14, where- 508,811 V V J1me 1955 in the deflector means includes an additional portion 1,10 ,208 France Sept. 211955 arched toward the rotor adjacent said helical flare. 1Q

Claims

1. A LIQUID-COOLED ELECTRICAL MACHINE COMPRISING A POLAR FIELD MEMBER, AN INDUCTOR DRUM SURROUNDING SAID FIELD MEMBER AND SPACED THEREFROM BY A MAGNETIC GAP, A COOLANT DEFLECTOR ADJACENT THE OUTSIDE OF THE PERIPHERAL WALL OF SAID DRUM, SAID DEFLECTOR EXTENDING SUBSTANTIALLY AROUND SAID DRUM, A ROTATABLE MEMBER SUPPORTING SAID DRUM AT ONE END THEREOF, SAID ROTATABLE MEMBER HAVING A DAM-FORMING TROUGH ON THE INSIDE THEREOF, MEANS PROVIDING OPENINGS EXTENDING FROM THE INSIDE OF SAID ROTATABLE MEMBER FROM THE TROUGH TO THE OUTSIDE OF SAID DRUM, SAID TROUGH BEING ADAPTED TO RECEIVE COOLANT WHEN SAID ROTATABLE MEMBER IS ROTATED AND DELIVER COOLANT CENTRIFUGALLY TO SAID OPENINGS FOR MOVEMENT THERETHROUGH TOWARD SAID DEFLECTOR, SAID DEFLECTOR BEING ADAPTED TO REVERT COOLANT FROM SAID OPENINGS TOWARD SAID DRUM, MEANS FOR DELIVERING COOLANT TO SAID TROUGH, AND COMMUNICATING MEANS BETWEEN THE TROUGH AND AROUND SAID DAM ADAPTED TO CARRY ANY SPILL-OVER OF COOLANT FROM THE TROUGH OVER THE DAM TO SAID GAP, SAID DRUM BEING OPEN AT ITS OTHER END FOR ESCAPE OF COOLANT FROM THE GAP.