US3641375A - Torque-transmitting device - Google Patents

Torque-transmitting device Download PDF

Info

Publication number
US3641375A
US3641375A US69702A US3641375DA US3641375A US 3641375 A US3641375 A US 3641375A US 69702 A US69702 A US 69702A US 3641375D A US3641375D A US 3641375DA US 3641375 A US3641375 A US 3641375A
Authority
US
United States
Prior art keywords
cooling medium
torque
members
transmitting device
grooves
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US69702A
Other languages
English (en)
Inventor
William H Moyer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eaton Corp
Original Assignee
Eaton Yale and Towne Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eaton Yale and Towne Inc filed Critical Eaton Yale and Towne Inc
Application granted granted Critical
Publication of US3641375A publication Critical patent/US3641375A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K49/00—Dynamo-electric clutches; Dynamo-electric brakes
    • H02K49/02—Dynamo-electric clutches; Dynamo-electric brakes of the asynchronous induction type
    • H02K49/04—Dynamo-electric clutches; Dynamo-electric brakes of the asynchronous induction type of the eddy-current hysteresis type
    • H02K49/043—Dynamo-electric clutches; Dynamo-electric brakes of the asynchronous induction type of the eddy-current hysteresis type with a radial airgap

Definitions

  • An electromagnetic torque-transmitting device or coupling includes a housing for enclosing a drum which extends around and is magnetically coupled with a rotor.
  • the housing defines a chamber which is pressurized with a suitable cooling medium, such as air, which flows around the coupling to cool it during a transmission of torque between the drum and rotor.
  • the pressurized cooling air flows into pockets spaced around the drum and impinges against the drum at circumferenu'ally spaced locations around the drum while passing under a baffle to an exhaust pocket; The cooling air is then exhausted to the atmosphere through conveniently located openings.
  • a plurality of circumferentially extending grooves are formed in an outer wall of the drum to further promote a transfer of heat from the drum to the cooling air.
  • the present invention relates to a torque-transmitting device, and more particularly to a cooling system for cooling an electromagnetic coupling which interconnects driving and driven members. It is well recognized in the art that the term coupling includes clutches, brakes, dynamometers and the like.
  • a known electromagnetic coupling includes a rotor which is disposed within a rotatable drum.
  • a coil is energized to generate a magnetic field which magnetically interconnects the rotor and drum so that torque can be transmitted between them.
  • the passage of this magnetic field through the rotor and drum results in the generation of heat while torque is being transmitted therebetween.
  • the dissipation of this heat has been a constant problem and many efforts have been made to effectively dissipate the heat.
  • heat dissipating fins are provided which extend from the exterior of the drum. However, these fins are difficult to form and may create such a loud noise that a silencer is required. Moreover, the fins also do not provide the most effective cooling of the coupling.
  • grooved drums have been provided and US. Pat. No. 2,345,850 illustrates an example of such. However, all efforts to date have not been completely satisfactory.
  • the present invention provides an extremely effective cooling system for a torque-transmitting device and which is free of many of the prior art problems.
  • the present system utilizes air which is pressurized so as to have a relatively high density as a cooling medium.
  • the pressurized air is provided by a blower which is associated with the coupling and directs air into a housing for the coupling.
  • the pressurized air provides the necessary energy to cause the air velocity to increase as it passes from an inlet air pocket, under a baffie, and to an exhaust pocket. This increase in velocity improves the heat transfer coefficient between the air and a surface to be cooled thereby.
  • the result is an effective dissipation of the heat which is generated by the transmission of torque between the input and output members.
  • the inductor drum As the inductor drum rotates centrifugal force causes the air to leave the drum. In order to supply adequate cooling fluid sufficient pressure must be furnished to, overcome the centrifugal velocity pressure. At higher drum speeds cooling fluid pressure must be increased proportionately.
  • the inductor drum is capable of dissipating l thermal horsepower in free air and eighty thermal horsepower pressurized. Tests have been made that indicate an improvement is made in the capacity of the air to dissipate heat when the pressure and density are increased.
  • the torque-transmitting device of the present invention minimizes the use of cooling fins and, yet, maintains a relatively large surface area for heat transfer through the provision of a grooved drum forming one of the input or output members. These grooves are readily machined in the drum as opposed to the difiiculties heretofore encountered in forming fins on the drum.
  • the cooling medium is distributed in spaced circumferential pockets around the input and output members and exhaust openings are located adjacent to these pockets.
  • the pockets are disposed so that a given point on one of the members sequentially passes the pockets and is exposed to the cooling medium therein and the exhaust openings.
  • Another object of this invention is to provide a new and improved torque-transmitting device having a means for effecting the transmission of torque between input and output members in a manner which tends to generate heat as torque is transmitted and wherein cooling fluid is directed under pressure into a housing for the members and into a heat-transferring relationship with the input and output members to at least partially dissipate heat generated during the transmission of torque between the input and output members.
  • Still another object of the present invention is to provide a new and improved torque-transmitting device, as set forth in the next preceding object, wherein the housing includes a plurality of baffles which cause the cooling fluid to impinge against at least one of the members at a plurality of circumferentially spaced locations before being exhausted through a plurality of openings in the housing.
  • Another object of this invention is to provide a new and improved torque-transmitting device having a housing forming a chamber for enclosing rotatable input and output members and wherein the housing defines a plurality of pockets and exhaust openings disposed in such an arrangement that a grooved surface of one of the members is sequentially subjected to a cooling medium in the pockets as the grooved surface rotates past the pockets.
  • FIG. 1 is a sectional view of a torque-transmitting device constructed in accordance with the present invention and illustrating the relationship between a rotatable drum or input member of a coupling assembly and an associated housing;
  • FIG. 2 is a fragmentary sectional view, taken generally along the line 2-2 of FIG. 1, and further illustrating the relationship between one of the grooves formed in the drum of the coupling and the housing;
  • FIG. 3 is a plan view, taken generally along the line 3-3 of FIG. 1, illustrating the relationship between a plurality of outlets forrned in the housing and the drum.
  • the present invention provides a torque-transmitting device 10 for transmitting torque from an input shaft 12 which is driven from a suitable source of power to an output shaft 14 which is connected with a driven machine or assembly.
  • the torque-transmitting assembly 10 includes a coupling 18 which is located within a generally cylindrical housing 20.
  • the coupling 18 is of a known electromagnetic type and includes a rotor or output member 24 which is disposed within a cylindrical work chamber 26 in a drum or input member 28.
  • a plurality of coils 32 mounted on poles of the rotor 24 are energizable to generate a magnetic field which extends from the rotor 24 into the drum 28 to magnetically couple the rotor 24 and the drum 28.
  • the coils 32 could be mounted in a stationary relationship with the housing 20.
  • the present invention is directed to an improved system for effectively dissipating the aforementioned heat which is generated by torque transmission.
  • a plurality of grooves 48 are formed in the drum 28 to increase the surface area of the drum and promote the transfer of heat to a cooling medium which contacts the drum.
  • the annular grooves 48 are formed in a cylindrical wall 50 of the drum 28 and are concentric with the axis of rotation of the drum and the shafts l2 and 14.
  • the grooves 48 being concentric with the axis of the drum, can be readily formed by known manufacturing techniques including machining.
  • the cooling of the drum 28 is effected by the flow of a cooling medium over surfaces thereof and, specifically, by the flow of a cooling medium through the grooves 48 therein. While many different known types of cooling mediums could be used for this purpose, in the illustrated embodiment of the invention, air is utilized as the cooling medium.
  • the coupling 18 can be cooled by admitting air at atmospheric pressure into the housing through suitable openings, the coupling 18 is most effectively cooled by pressurizing a chamber 54 within the housing 20. This increases the density of the air and promotes a flow of the air around baffle plates 56 of a manifold arrangement 58 and into the grooves 48 wherein the air is heated to cool the drum 28. This heated air then flows out of the housing through rectangular openings 60 disposed at spaced apart locations along a cylindrical wall 62 of the housing (see FIGS. 2 and 3). Cooperation between the baffle plates 56 and the rotating drum 28 further induces a flow of air from manifold chambers 66 into the grooves 48 and from there through the openings 60.
  • air under pressure is conducted into the chamber 54 through an inlet duct 70 which extends'between the housing 20 and a suitable blower or other compressor (not shown).
  • a plurality of movable louvers or slats 72 are provided in the duct 70 immediately adjacent to an opening 74 (FIG. 1) in the housing 20 to facilitate controlling the flow of air through the opening in a known manner. While the use of an external compressor or blower is preferred, since its output is independent of the speed of operation of the torque-transmitting device 10, it is contemplated that a blower or compressor could be provided as part of the input or output member, within the housing 20.
  • the relatively high pressure cooling air enters the chamber 54, it tends to flow outwardly into the longitudinally extending manifold chambers or pockets 66 (FIGS. 2 and 3) formed at circumferentially spaced locations around the drum 28.
  • the baffle plates 56 and pockets 66 extend lengthwise of the housing 20 between circular end walls 76 and 78 of the housing. Therefore, as the drum 28 rotates, it is sequentially exposed to the relatively dense, pressurized cooling air in each of the pockets 66 in turn.
  • the air After the air has moved in a generally axial direction along the manifold chambers or pockets 66, the air flows inwardly around inner ends or edges 80 of the baffle plates 56 into the grooves 48. As the air flows inwardly, it impinges against the grooved surface of the drum 28. The direction of flow of the air then changes so that it moves circumferentially around the drum 28 in the manner indicated schematically by the arrows in FIGS. 2 and 3. It is believed that as the air flows inwardly around the inner edges 80 of the baffle plates 56, the air tends to be packed or compressed into the grooves 48 under the influence of both the relatively high pressure in the pockets 66 and the drum 28 which is rotating at a relatively high speed past the stationary baffle plates.
  • rings 84 may be omitted in certain torque-transmitting devices which can be adequately cooled by a flow of pressurized air into engagement with a smooth surfaced drum.
  • the heated air After heat has been transferred to the pressurized air from the drum 28;, the heated air enters exhaust pockets 88 circumferentially located around the drum 28 and in between the inlet pockets 66.
  • the heated air is exhausted to the atmosphere through either outlets 60 (H68. 2 and 3) at the outer wall 62 of the housing 20, or by connecting the exhaust pockets 88 to a common exhaust chamber and thence to the atmosphere through conveniently located openings in the housing '20..
  • the drum 28 cooperates with the baffle plates 56 to define therebetween aplurality of relatively small elongated openings (see FIG. 1) which extend parallel to the axis of rotation of the drum. These openings 90 have inwardly projecting teeth or fingers formed by the grooves 48.
  • the combined area of all of the openings 90 formed between the inner edges of the baffle plates 56 and the drum 28 is less than the cross-sectional area of the opening 74 in the duct 70. Therefore, the chamber 54 can be readily pressurized to a desired level by a flow of air under pressure from a fan or blower. Pressurizing the chamber 54 advantageously promotes a flow of air through the openings to the atmosphere which is at a somewhat lower pressure.
  • the rotor 24 has a plurality of openings, indicated generally at 94 in FlG. 1, through which air flows in a generally axial direction, as indicated by the arrows in FIG. 1. Of course, this flow of air cools the rotor 24.
  • the air heated by the rotor 24 then flows through openings 98 in a circular end wall 100 of the drum 28. The heated air then flows around the end baffle plates 104 and the axially extending baffle plates 56 to the outlet 88 with the air from the grooves 48 in the drum.
  • This flow of air around the rotor 24 is promoted by fins 108 which extend outwardly from the end wall 100 of the drum 28.
  • the fins 108 may be eliminated with the use of external blowers or may be used in an internal blower with air entering from an opening through wall 76 (not shown). This would necessitate a reversing of the direction of air flow through the coupling. However, cooling the drum with pressurized air would still be effected.
  • the cooperation between the grooves 48 and the circumferentially spaced outlets 88 enables the drum 28 to be effectively cooled without generating a relatively high level of noise.
  • the flow of air through the grooves and around the baffle plates 56 is so quiet that it is not necessary to use a silencer as heretofore utilized with certain types of couplings having fins connected to their outer surface to promote cooling. it is believed that this relatively quiet operation of the torque-transmitting device 10 may be due to a relatively smooth flow of air through the grooves 48.
  • the torque-transmitting device includes an electromagnetic coupling 18 having a drum 28 and a rotor 24 which tend to become heated as torque is transmitted from the input shaft 12 to the output shaft 14.
  • the drum 28 has a plurality of rings 84 which define circumferentially extending grooves 48 in the outer surface of the drum.
  • the coupling 18 is enclosed by a housing 20 having baffle plates 56 which form circumferentially spaced pockets 66 to which the surface of the drum 28 is sequentially exposed as it rotates. Heat is transferred at a relatively high rate from the surface of the grooved drum 28 to the relatively dense cooling air.
  • This heated air is exhausted through the openings 60 with a minimum of noise to at least partially dissipate the heat generated upon the transfer of torque between the drum 28 and rotor 24.
  • air is utilized as the cooling medium in the illustrated embodiment of the invention, it is contemplated that in different environments other fluids will be utilized as a cooling medium and, in certain environments, the cooling medium may even take the form of a liquid.
  • a salient pole-type coupling 18 has been illustrated herein, it should be understood that the present invention can be used with other types of couplings. Specifically, the coupling could be of the well-known stationary field eddy current type. Moreover, while the present invention has been disclosed as being utilized in an electromagnetic coupling, it should be appreciated that the concept of the present invention is equally applicable to dynamometers and electromagnetic brakes. Also the pole configuration could be of the interdigited type. A coupling of this type is illustrated in US. Pat. No. 3,217,197 and the present invention may be applied thereto. The interaction between a grooved drum of any of these and other known types of couplings with the pressurized air in a housing, similar to the housing 20, would be substantially the same and would result in improved cooling of the coupling.
  • a torque-transmitting device comprising a first member, a second member rotatable relative to said first member, means for effecting the transmission of torque between said first and second members in a manner which generates heat as torque is transmitted therebetween, housing means enclosing said first and second members and defining a chamber for receiving a cooling medium for dissipating at least in part the heat generated by the transmission of torque between the first and second members, outlet means disposed in said housing means for providing an egress for said cooling medium from said housing means, said second member establishing a cen trifugal force which acts to direct the cooling medium away from said second member upon rotation of said second member relative to said first member, and means for providing a flow of cooling medium into said housing means under a pressure which is greater than the pressure effected by said centrifugal force established by said second member acting on the cooling medium to enable the cooling medium to move against said centrifugal force into a heat-transferring relationship with said first and second members whereby the pressurized cooling medium effects efficient transfer of heat from said members.
  • said baffle means includes a plurality of walls each of which extends axially of said one member and has an inner end portion which is disposed adjacent to and cooperates with said grooves in said one member to at least partially define a passage through which at least a portion of the cooling medium flows prior to entering said grooves.
  • said housing means includes an outer wall having a plurality of openings therein at spaced apart locations which cooperate to form said outlet means, a plurality of baffle plates extending inwardly from said wall toward said members and having innermost edge portions which cooperate with an outer surface means of one of said members to at least partially define passages through which fluid can flow under pressure to said openings.
  • a torque-transmitting device comprising relatively rotatable first and second members, means for transmitting torque between said first and said second members in a manner which generates heat, a housing for said first and second members defining a chamber for a cooling medium for dissipating the heat generated upon torque transmission between said first and second members, means in said housing defining a plurality of pockets for the cooling medium at circumferentially spaced locations around one of said members, and means defining a plurality of exhaust openings adjacent said pockets for directing cooling medium from the chamber, said one of said members having a grooved surface portion which rotates past said pockets and said exhaust openings during transmission of torque between said members, said grooved surface portion being sequentially subjected to the cooling medium in said pockets as it rotates and at least partially defining a passage for flow of fluid from said pockets to said exhaust openings.
  • a torque-transmitting device as set forth in claim 11 further including means for maintaining the cooling medium in said pockets under pressure to thereby promote a flow of the cooling medium from said pockets and through said passage to said exhaust openings.
  • An electromagnetic torque-transmitting device comprising rotatable input and output members, an electrical coil associated with said input and output members and energizable to create a magnetic field traversing said members so that relative rotation of said members generates heat and effects transmission therebetween, housing means at least partially enclosing said input and output members and defining a chamber for receiving cooling medium for dissipating at least in part the heat generated by the transmission of torque between the input and output members, and means for providing a flow of the cooling medium into said housing means and providing pressurized cooling medium therein in a heat-transferring relationship with said input and output members whereby the pressurized cooling medium effects efficient transfer of heat from said members, said housing means including baffle means for directing the cooling medium to impinge against said one member at a plurality of circumferentially spaced locations.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • General Details Of Gearings (AREA)
  • Mechanical Operated Clutches (AREA)
  • Dynamo-Electric Clutches, Dynamo-Electric Brakes (AREA)
  • Motor Or Generator Cooling System (AREA)
US69702A 1970-09-04 1970-09-04 Torque-transmitting device Expired - Lifetime US3641375A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US6970270A 1970-09-04 1970-09-04

Publications (1)

Publication Number Publication Date
US3641375A true US3641375A (en) 1972-02-08

Family

ID=22090672

Family Applications (1)

Application Number Title Priority Date Filing Date
US69702A Expired - Lifetime US3641375A (en) 1970-09-04 1970-09-04 Torque-transmitting device

Country Status (10)

Country Link
US (1) US3641375A (xx)
AU (1) AU446849B2 (xx)
BE (1) BE772112A (xx)
BR (1) BR7105827D0 (xx)
CA (1) CA931514A (xx)
ES (1) ES200815Y (xx)
FR (1) FR2107223A5 (xx)
GB (1) GB1368078A (xx)
IT (1) IT943600B (xx)
NL (1) NL7112038A (xx)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2522423A1 (de) * 1974-06-28 1976-01-15 Heenan Drives Ltd Elektromagnetische kupplung
US3996485A (en) * 1974-06-28 1976-12-07 Eaton Corporation Electromagnetic coupling and cooling system therefor
US4362958A (en) * 1980-11-03 1982-12-07 Eaton Corporation Electromagnetic coupling and cooling system therefor
EP0367387A2 (en) * 1988-10-31 1990-05-09 Sumitomo Metal Industries, Ltd. Eddy current retarder
US5698913A (en) * 1995-06-15 1997-12-16 Kabushiki Kaisha Toshiba Outer-rotor type electric rotary machine and electric motor vehicle using the machine
EP0879973A1 (en) * 1997-05-23 1998-11-25 General Motors Corporation Magnetorheological transmission clutch
US6460661B1 (en) * 1998-09-21 2002-10-08 Robert Bosch Gmbh Electrical brake having a holding brake function

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2345850A (en) * 1942-04-13 1944-04-04 Martin P Winther Cooling apparatus
US3056895A (en) * 1957-12-17 1962-10-02 Cohen Elie Electromagnetic coupling

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2345850A (en) * 1942-04-13 1944-04-04 Martin P Winther Cooling apparatus
US3056895A (en) * 1957-12-17 1962-10-02 Cohen Elie Electromagnetic coupling

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2522423A1 (de) * 1974-06-28 1976-01-15 Heenan Drives Ltd Elektromagnetische kupplung
US3996485A (en) * 1974-06-28 1976-12-07 Eaton Corporation Electromagnetic coupling and cooling system therefor
US4362958A (en) * 1980-11-03 1982-12-07 Eaton Corporation Electromagnetic coupling and cooling system therefor
EP0367387A2 (en) * 1988-10-31 1990-05-09 Sumitomo Metal Industries, Ltd. Eddy current retarder
EP0367387A3 (en) * 1988-10-31 1991-08-07 Sumitomo Metal Industries, Ltd. Eddy current retarder
US5698913A (en) * 1995-06-15 1997-12-16 Kabushiki Kaisha Toshiba Outer-rotor type electric rotary machine and electric motor vehicle using the machine
EP0879973A1 (en) * 1997-05-23 1998-11-25 General Motors Corporation Magnetorheological transmission clutch
US6460661B1 (en) * 1998-09-21 2002-10-08 Robert Bosch Gmbh Electrical brake having a holding brake function

Also Published As

Publication number Publication date
BE772112A (fr) 1972-01-17
ES200815Y (es) 1976-01-16
BR7105827D0 (pt) 1973-05-10
CA931514A (en) 1973-08-07
IT943600B (it) 1973-04-10
AU446849B2 (en) 1974-04-04
ES200815U (es) 1975-09-01
AU3282671A (en) 1973-03-01
DE2143400A1 (de) 1972-03-09
DE2143400B2 (de) 1977-06-08
FR2107223A5 (xx) 1972-05-05
NL7112038A (xx) 1972-03-07
GB1368078A (en) 1974-09-25

Similar Documents

Publication Publication Date Title
US3566168A (en) Eddy current rotary machine having torque transmission arrangement
US3458122A (en) Ventilating device for cooling a heat engine
US3036680A (en) Electromagnetic couplings
US3020427A (en) Ventilation of dynamoelectric machine drive units
US3863083A (en) Fluid-cooled dynamometer
JPH04229050A (ja) 回転子液冷式の回転電気機械
US3641375A (en) Torque-transmitting device
US2745974A (en) Eddy current torque producing device
GB1397302A (en) Cooling dynamoelectric machines
US3455419A (en) Magnetic coupling devices
US4085344A (en) Cooling for magnetic particle devices
US2334976A (en) Eddy-current coupling
US3478239A (en) Eddy-current coupling
US4780637A (en) Brushless eddy current coupling - stationary field
US3076109A (en) Air-cooled eddy-current coupling and brake
JPS5825027B2 (ja) 渦電流接手
US3996485A (en) Electromagnetic coupling and cooling system therefor
US2640941A (en) Eddy current mechanism
US2287953A (en) Electrical apparatus
US2908834A (en) Air-cooled eddy current coupler device
US2944647A (en) Air cooled clutch-brake
US3353042A (en) Ventilation for totally enclosed dynamoelectric machine
US2827580A (en) Dynamoelectric rotor with cooling fins
US3198975A (en) Eddy current coupling
US2185728A (en) Dynamo-electric machine