US2803764A

US2803764A - Liquid cooled electromagnetic apparatus

Info

Publication number: US2803764A
Application number: US331953A
Authority: US
Inventors: Henry P Lundskow
Original assignee: Eaton Manufacturing Co
Current assignee: Eaton Corp
Priority date: 1953-01-19
Filing date: 1953-01-19
Publication date: 1957-08-20
Anticipated expiration: 1974-08-20

Description

1957 H. P. LUNDSKOW 2,803,764

LIQUID COOLED ELECTROMAGNETIC APPARATUS Filed Jan. 19, 1955 2 Sheets-Sheet l INVENTOR. HENRY P. Lunnsxow H. P. LUNDSKOW LIQUID COOLED ELECTROMAGNETIC APPARATUS Aug. 20, 1957 2 Sheets-Sheet 2 ailllllilitiflllliln Filed Jan. 19, 1953 INVENTOR.

HENRY P Luuosxow United States Patent O7 LIQUID COOLED ELECTROMAGNETIC APPARATUS Henry P. Lundskow, Kenosha, was, assignor, by mesne assignments, to Eaton Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application January 19, 1953, Serial No. 331,953

9 Claims. (Cl. 310-93) This invention relates to electromagnetic clutches and the like and more particularly to liquid cooled eddy current clutches and dynamometers.

In the liquid cooling of eddy current clutches and dynamometers wherein the cooling liquid is circulated directly to the eddy current surfaces of said mechanisms, undesirable oscillation, hydraulic surge or fluctuation of the mechanism occurs due to liquid slugging, turbulence or uneven distribution of the liquid over the eddy current surfaces of the mechanism. This condition can be remedied by introducing a small amount of air or non-explosive gas to the liquid to be circulated over the eddy current surfaces of the mechanism for the cooling thereof.

Among the principal objects of the invention is the provision of eddy current clutches or dynamometers hav ing liquid circulated through the eddy current flux gap thereof for cooling purposes, in which:

a. Air is introduced into the cooling liquid effective to produce an effervescent condition of the liquid whereby it may be evenly distributed across the eddy current surfaces;

b. Oscillation or fluctuation due to water surging, turbulence or uneven distribution of the cooling liquid is practically eliminated;

c. The cooling liquid is aerated and as such as effectivgly distributedover and wets the eddy current surfaces; an

d. Air or non-explosive gas is added to the cooling liquid for reducing disturbance in speed of the clutches or dynamometers.

Other objects and advantages of the invention will appear from the following description taken in connection with the drawings forming a part of the specification; and in which:

Fig. 1 is a vertical cross-sectional view of a dynamometer embodying the invention; and

Fig. 2 is a fragmentary partly cross-sectional partly broken away view of the liquid and air or non-explosive gas coupling for the dynamometer of Fig. 1.

Fig. 3 is a crosssectional partly broken away view taken substantially along lines 33 of Fig. 1.

It has been determined that by the addition of air or non-explosive gas to the liquid to be circulated through the eddy current flux gap of dynamometers, driving and absorbing dynamometers, and variable speed clutches for the cooling thereof, undesirable oscillations or fluctuations due to liquid slugging, turbulence or uneven distribution of the cooling liquid is practically eliminated thereby providing for the steadier and more eflicient operation of the mechanism.

Through the addition of air or non-explosive gas to the cooling liquid, an effervescent or aerated condition is produced permitting of a uniform distribution of the cooling ice liquid, an effective filling of the magnetic flux gap and an effective wetting of the eddy current surfaces adjacent the gap.

Referring to the drawings for more specific details of the invention 10 represents generally a dynamometer, a rocking stator 12 of which is supported upon axially spaced bearings 14 mounted on supporting pedestals 16. Stator 12 comprises

end closure plates

18 and 20 respectively having an internally interdigitated toothed cylinder 22 bolted therebetween, said cylinder being made of suitable magnetic material. I

Axially opposite extended sleeve portions 24 and 26 of the

respective plates

18 and 20 are arranged internally of the spaced bearings 14 for rocking motion support thereon. Bearings 28 are mounted in axially spaced relation internally of the respective sleeve portions 24 and 26 of

plates

18 and 20 and in turn support thereon a rotary twopart drive shaft 30 which passes through water seals 32. Seals 32 are spaced from one another and are supported in annular flanged members 34 bolted to the respective

end closure plates

18 and 20 axially inwardly of the respective sleeve portions 24 and 26 thereof. As such a liquid tight chamber 36 is provided internally of the

end closure plates

18 and 20 and cylinder 22, the purpose of which will hereinafter appear.

Shaft 30 axially intermediate the seals 32 is bolted to the hub 38 of a supporting spider 40 of rotor 42. An eddy current cylindrical drum 44 is fixedly secured to the outer periphery of spider 40. Drum 44 has a smooth external cylindrical surface and is made of a suitable magnetic material.

Cylinder 22 of stator 12 is composite in structure and includes an outer ring 46, internal oppositely disposed rings 48 bolted to ring 46 and respectively to the

end closure plates

18 and 20. An annular space 50 is provided axially between portions of rings 48 within which an annular electromagnetic coil 52 is securely arranged, supplied electric current from a source, not shown. Each of the rings 48 includes on its inner periphery a series of circumferentially spaced axially extended polar teeth 54 arranged in interdigitated relation to the teeth on the other ring 48 radially internally of the coil 52. The teeth 54 are provided on their inner diameter with curved surfaces Which lie in a common cylindrical surface spaced a predetermined amount from the external cylindrical surface of drum 44. This space A designates the magnetic flux gap between the rotor and stator of the dynamometer. The combined axial width of the polar teeth 54 is substantially identical with the axial width of the drum 44 whereby eddy currents are confined to radial flow therebetween.

The portions of rings 48 bolted to

end cover plates

18 and 20 each have a greater diameter than the cylindrical surfaces of polar teeth 54 such that by reason of provision of cooperative axially extended

flanges

56 and 58 respectively on spider 40 and end cover plate 20 a confined annular chamber 60 is provided to one side of drum 44 :and through structural cooperation between an axially extended portion 62 of end cover plate 18 and a portion of drum 44 a chamber 64 is provided on the opposite side of drum 44 from chamber 60. Chambers 60 and 64 communicate with space A at opposite ends thereof.

Liquid for cooling the dynamometer effective to communicate with the space A between the cylindrical surfaces of the stator and rotor is fed by way of liquid conduits 66 extending through the rings 48 into the space between the interdigitated teeth 54 from whence it communicates with space A. Conduits 66 are supplied cooling liquid by way of suitable piping including conduits 68, T connection 7% nipple connection 72, T connection 74 and conduit '76 with conduit 76 being connected to the source of cooling liquid. As shown more clearly in Figure 2 one branch 73 of T connection 74 is connected to nipple '72 and another branch 80 is connected to conduit 76, the third branch 82 is connected by angular nipple 84 and suitable conduit as to an air or non-explosive gas supply. A sleeve 88 of smaller diameter than the inner diameter of T connection 7 is connected at one end to nipple 84 with the sleeve extending between

branches

82 and 78 of the T connection 7% and bridging the opening through branch 80 such that air as admitted, through sleeve 88, flows downstream in the direction of flow with the liquid supplied by conduit 76.

The bottom of chambers 64) and 64 provide respective sumps 90 and 92 to which are connected outlet conduits 94 extending through the portions of rings 48 bolted to the respective end closure plates 18 and 2t) into communication with the sumps 9t) and 92. Conduit 94 serve to drain the cooling liquid delivered to the dynamometer for its subsequent delivery handling either for re-use or outright disposal.

End rings 96 arranged on the external opposite axial ends of teeth 54 serve to confine the liquid which is fed to the dynamometer for passage through space A for effectively cooling the dynamometer. A small clearance is provided between the internal periphery of the rings and external periphery of the drum whereby the liquid discharged from the space A can be effectively controlled. Rings 96 as seen in Figs. 1 and 3 of the drawings have openings provided therein adjacent the sumps 9t) and 92 permitting the liquid, discharged from space A into chambers 6% and 64, to pass easily and quickly to the sumps 90 and 92. A pair of oppositely angularly disposed baflles 1% are arranged in chord manner in the teeth portion of rings 48 as shown by Figs. 1 and 3 and serve to separate sumps 9t? and 92 from the confined liquid chamber 1G2 provided by end rings 96, the rings 48 and the drum thereby necessitating the flow of liquid between the inner periphery of end rings 96 and external periphery of drum 4-4.

By so confining the liquid to flow in chamber 102 and space A an entire filling of effervescent liquid between the teeth and external surface of the drum is possible whereby the effervescent liquid is equally distributed across the entire surface of the drum.

By providing for the introduction of air or non-explosive gas into the cooling liquid an effervescent or aerated condition is produced such that this effervescent liquid in being fed into the chambers 6t? and 64 at the top of the dynamometer is drawn through the eddy'current iiux gap under the action of relative rotation occurring between the cooperative eddy current surfaces of the stator and rotor. With the coil 52 energized and with the shaft being rotated the heat generated due to eddy current flow between the rotor and stator as they are rotated relative to one another is extracted therefrom by the effervescent liquid passing through space A. By reason of the effervescence of the liquid, at more uniform distribution and effective wetting action of the liquid occurs across the cooperative eddycurrent surfaces of the stator and rotor and between the interdigitated polar teeth 54. In so being uniformly distributed the cooling liquid serves to maintain a uniform balance or cushion effect between the stator and rotor such that a uniform and steady condition of operation results at the output of the dynamometer thereby accounting for virtually eliminating undesirable oscillation or fluctuation that might otherwise occur.

The effervescent liquid delivered to the

chambers

56 and 58 upon serving its cooling function passes to sumps 90 and 92 from where it is drained from the dynamometer.

Although the invention has been described specifically both as to the form of liquid aerating means and the mechanism to which applied, it is readily conceivable that the basic premise taught is applicable to any of several like electro-magnetic mechanisms wherein the cooling thereof is accomplished by the introduction of the cooling liquid into the flux flow path between relatively rotatable parts thereof and further that any means capable of producing an effervescent condition in the cooling liquid can be utilized without departing from the scope of the invention. Accordingly, the invention is to be interpreted in the light of the aforesaid recitations as evidenced by the appended claims wherein the term clutch is to be understood as embracing mechanisms such as brakes, clutches and dynamometers.

What I claim is:

1. In mechanism of the class described, a magnetic stator member, a magnetic rotor member, an annular coil carried by one of the members, end members secured to the stator member and forming a liquid tight compartment around the rotor member, a plurality of interdigitated, axially spaced polar teeth on one member spaced from a cooperative portion of the other member and ring means arranged at the remote ends of said axially spaced teeth and partially enclosing the space between said teeth and said cooperative portion of said other member, said coil providing a magnetic flux field passing through the rotor and stator between the polar teeth on the one member and the cooperative portion of the other member, means introducing effervescent cooling liquid for circulation in the liquid tight compartment and between the polar teeth on the one member and the cooperative portion of the other member, and said end ring means restricting the flow of cooling liquid away from the space between said polar teeth and said cooperative portion of said other member.

2. In mechanism according to claim 1 wherein the polar teeth are arranged on the stator at the inner periphery thereof and wherein the cooperative portion of the rotor is radially spaced therefrom.

3. In mechanism according to claim 2 wherein the cooperative portion of the rotor presents a cylindrical surface to the polar teeth and wherein the coil is arranged on the stator.

4. In a mechanism of the class described, a cylindrical magnetic member, a magnetic rotor rotatable relative to said cylindrical member, flux concentrating teeth arranged in interdigitated array and extending inwardly from said cylindrical member, an annular coil carried in said cylindrical member and providing a flux field interlinking said cylindrical member and said rotor and passing through said teeth, enclosure means on said cylindrical member cooperating with said rotor to form a liquid tight compartment, bafile means extending between adjacent flux concentrating teeth, end ring means provided at the remote ends of said teeth, means for introducing effervescent liquid through said cylindrical member between said teeth of said cylindrical member, and said baffle means and said end ring means being arranged to direct the flow :of liquid radially between said teeth and the peripheral surface of said rotor.

5. A mechanism according to claim 4 wherein the inlet means are disposed to introduce the liquid into the compartment at axial opposite ends of the spaced cooperative portions of the members.

6. A mechanism according to claim 4 wherein means are provided for mixing air or non-explosive gas with the liquid to be introduced into the compartment.

7. A mechanism according to claim 4 wherein one of the members is a stator and the other a rotor.

8. A mechanism according to claim 7 wherein the stator is cylindrical and includes end closure members in enclosed relation to the rotor with the compartment therebetween.

9. A mechanism according to claim 8, wherein annu' lar chambers are provided on opposite axial ends of the space between the cooperative portions of the stator and References Cited in the file of this patent UNITED STATES PATENTS Breeze Oct. 27, 1914 Doyle May 31, 1927 6 Winther Ian. 9, 1945 Winther Jan. 16, 1945 Anderson Dec. 17, 1946 Hugin Mar. 18, 1947 FOREIGN PATENTS Great Britain Sept. 24, 1936 Great Britain May 20, 1946