US2923390A - Electrostatic clutch - Google Patents

Electrostatic clutch Download PDF

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Publication number
US2923390A
US2923390A US556676A US55667655A US2923390A US 2923390 A US2923390 A US 2923390A US 556676 A US556676 A US 556676A US 55667655 A US55667655 A US 55667655A US 2923390 A US2923390 A US 2923390A
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US
United States
Prior art keywords
clutch
electro
adhesive
semi
conductive
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
US556676A
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English (en)
Inventor
Clyde J Fitch
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.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
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 International Business Machines Corp filed Critical International Business Machines Corp
Priority to US556676A priority Critical patent/US2923390A/en
Priority to DEI12636A priority patent/DE1124612B/de
Priority to FR1179253D priority patent/FR1179253A/fr
Application granted granted Critical
Publication of US2923390A publication Critical patent/US2923390A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N13/00—Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H59/00—Electrostatic relays; Electro-adhesion relays

Definitions

  • This invention relates to electrostatic devices wherein the operation depends upon the electro-adhesive forces between a conductive member and a cooperating semiconductive member.
  • this invention is directed to electrostatic clutches wherein a driven member is clutched to a driving member by electro-adhesive forces.
  • a semi-conductor As used hereinafter, a semi-conductor will be defined as a resistance material having a resistivity within the general range of 106 to 10'z ohms per cubic centimeter.
  • amplified wear of the clutching surfaces was caused by dust particles acting as an abrasive between the surfaces. These dust particles were produced by wear, due to surface friction, and erosion, due to making and breaking electrical current passing through the surface contact. This amplified wear resulted in alterations of the quality of the clutching surfaces, i.e., smoothness and shape, and produced unstable and unreliable operation.
  • brushes were used as wipers to rcmove the abrasive particles. However, the brushes became saturated with the abrasive dust particles and ceased to function.
  • an electro-adhesive clutch Even though a primary advantage of an electro-adhesive clutch over other similar devices is rapid electrical response time (of the order of microseconds), this advantage has not, in practice, been available for most ice applications because of erratic operation and unreliability. In addition to rapid response time, an electro-adhesive clutch has many other potential advantages not found in similar devices. Low operating current (of the order of milliampere at 200 volts), non-inductive circuit operation, low manufacturing cost, and small size '1n relation to torque output are examples of these advantageS.
  • the present invention is directed to an electrostatic clutch employing novel electro-adhesive material, operable under severe frictional conditions, capable of withstanding relatively high operating temperatures and having constant stability under a wide range of operating conditions. Furthermore, the concept of operation of the present invention is based on electronic conductivity through the semi-conductor in order to eliminate adverse electrochemical effects, rather than on ionic conductivity.
  • the present invention also contemplates a novel electro-adhesive material comprising heterogeneous deposits of conductive or semi-conductive particles bonded together in an insulating binder.
  • Materials of this nature may comprise carbon particles in a rubber or phenolic binder, molded to shape, Vand cured, or carbon particles and/or metal oxides in a clay or ceramic binder, die pressed to shape and tired.
  • the present invention contemplates a novel electro-adhesive clutch wherein a permanent surface condition is maintained. This is accomplished by the use of an agent acting as a lubricant and scavenger in the clutch to lubricate and collect abrasive dust particles resulting from wear.
  • a primary object of this invention is to provide a stable and reliable electro-adhesive device.
  • Another object is to provide a reliable electro-adhesive clutch capable of operating at relatively high speeds.
  • a more particular object is to provide an improved electro-adhesive material.
  • Another object is to provide an improved electro-adhesive clutch wherein a substantially permanent surface condition is maintained.
  • a further object is to provide an electro-adhesive clutch with an improved semi-conductor.
  • Still another object is to provide an improved electroadhesive clutch wherein the abrasive elr'ect of particles of wear is eliminated.
  • Another object is to provide an improved semi-conductive clutch element wherein the electrical conductivity therethrough is electronic.
  • Another object of this invention is to provide an improved and lubricated electro-adhesive device.
  • Another object of this invention is to provide an electro-adhesive clutch reliable under a wide range of operating conditions.
  • Fig. 1 is a transverse vertical sectional view, partly diagrammatic, of an electro-adhesive clutch constructed in accordance with the present invention and taken along the line 1-1 of Fig. 2.
  • Fig. 2 is a partial sectional view taken along line 2-2 of Fig. 1.
  • a shaft 11 has a conductive hub 12, preferably of brass, secured thereto and has a pulley 13 mounted, by a bearing 14, to rotate freely thereon.
  • Pulley 13 has a metal ring 15 secured thereto by bolts 16, insulating sleeves 17 and insulating plugs 18. Thus ring 15 may be electrically isolated from hub 12.
  • Ring 15 has a contact brush 19 riding thereon and hub 12 has contact brush 21 riding thereon.
  • Brush 19 is connected to the negative terminal of a source of potential shown as a battery 22, and brush 21 is connected through a switch 23 to the positive terminal of the source.
  • An electro-adhesive material 24, described in more detail below, is bonded to hub 12 and forms a clutching surface 25,.
  • a conductive band 26, preferably of stainless steel, is secured at one end to ring 15 by a ⁇ member 27, so as to make electrical contact with ring 15.
  • the other end of band 26 is attached to one end of spring 28.
  • the other end of spring 28 is attached to ring 15 so Vthat spring 28 urges band 26 into contact with the surface 25.
  • a block of material 29, tetratiuorethylene resin, for example, the function of which will be described more fully below, is held against surface 25 by spring 31.
  • the block 29 and the spring 31 are carried by ring 15.
  • a brush 32, of mohair or the like, is carried by ring 15 to wipe the surface 25.
  • either the shaft 11 or the pulley 13 may be externally driven as desired by a motor, or the like, not shown.
  • switch 23 With switch 23 open, the surface 25 and the band 26 slide over one another.
  • switch 23 When switch 23 is closed, the potential of battery 22 is applied between band 26 and material 24, and the resulting electro-adhesive force between surface 25 and band 26 will clutch pulley 13 to shaft 11.
  • the clutch operates at either polarity; however, it is preferable that the band be the negative electrode and the semi-conductive material be the positive electrode.
  • the clutch also operates satisfactorily with an alternating current source.
  • hub 12 with material 24 bonded thereon, acts as the driving member of the clutch
  • band '26 acts as the driven member. If pulley 13 is externally driven, the opposite functions prevail as to driving and driven members.
  • the electro-adhesive material 24 is a semi-conductor comprised of conductive particles in an insulating binder.
  • One preferred material includes natural or synthetic rubber, phenolic, asbestos and carbon.
  • a material found to be quite satisfactory may be fabricated from the following proportions by weight of ingredients: 162 parts rubber, 200 parts phenolic resin, 240 parts asbestos, 6 parts zinc oxide, 6 parts sulphur, 3 parts stearic acid, 3 parts zinc stearate, 3 parts antioxidant, 1.5 parts mercaptobenzothiazole, .3 parts zinc dimethyl dithiocarbamate and 166 parts carbon black. With such a material bonded to hub 11 the surface 25 will contain many conductive particles, some of which are in contact with band 26.
  • a solid lubricating agent of high electrical resistance also acting as a scavenger, is placed to contact a clutching surface.
  • the agent wears and deposits a thin film on the clutching surface. Particles of the agent cling together and attract surface dust particles, possibly by triboelectric action, to thus eliminate the abrasive action of the dust particles.
  • a block of tetrafluorethylene resin has been ,found to be quite satisfactory as a lubricating and scavenger agent.
  • a block of tetrauorethylene resin 29 is carried by ring 15 and urged against surface 25 by spring 3'1. With this arrangement, wear of the semi-conductor is controlled.
  • a brush 32 is also provided, though not necessary, to remove any large accumulations of the tetrafluoroethylene resin.
  • an electro-adhesive clutch may be given a long life of stable and reliable operation, even at high speeds.
  • Such a clutch is well suited to many high speed clutching needs not before satisfied.
  • This clutch also has a relatively high torque at zero slip speed, thus enabling synchronous operation through the clutch.
  • electro-adhesionf is a surface phenomenon, and maintenance of proper surface conditions in an electroadhesive clutch is of vital importance in securing reliable operation. Proper surface conditions may be maintained in a clutch comprising the above-described material and lubricating agent.
  • An electro-adhesive device comprising in combination, a conductive member having a first surface, a semiconductive member formed of a heterogeneous mixture comprised of rubber, phenolic, asbestos and carbon and having a second surface disposed to slidably contact said first surface, means for moving said members relatively to each other along their contacting surfaces, a body of tetrauorethylene resin disposed to slidably contact one of said surfaces, and means for applying an electrical potential difference between said surfaces.
  • An electro-adhesive clutch comprising in combination, a rotatable semi-conductive body comprised of electrically conductive particles bound together by an electrically insulating binding agent and having a first sur.- face, an electrically conductive body having a second surface disposed to slideably contact said first surface, and means for applying an electrical potential difference between said surfaces.
  • said semiconductive body is a heterogeneous mixture comprised of rubber, phenolic, asbestos and carbon.
  • An electro-adhesive clutch comprising in combination, a first rotatable member comprised of a body of semi-conductive material formed of a heterogeneous mixture comprised of rubber, phenolic, asbestos and carbon and having a first surface, a second rotatable member comprised of an electrically conductive body having a second surface disposed to slidably contact said first surface, a body comprised of a lubricating agent carried by one of said members and disposed to slidably contact the cooperating surface of the other, and means for apfaces.

Landscapes

  • Lubricants (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Braking Arrangements (AREA)
  • Mechanical Operated Clutches (AREA)
US556676A 1955-12-30 1955-12-30 Electrostatic clutch Expired - Lifetime US2923390A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US556676A US2923390A (en) 1955-12-30 1955-12-30 Electrostatic clutch
DEI12636A DE1124612B (de) 1955-12-30 1956-12-22 Vorrichtung zur elektrisch steuerbaren UEbertragung von mechanischen Kraeften
FR1179253D FR1179253A (fr) 1955-12-30 1956-12-27 Embrayage électrostatique

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US55664455A 1955-12-30 1955-12-30
US556676A US2923390A (en) 1955-12-30 1955-12-30 Electrostatic clutch

Publications (1)

Publication Number Publication Date
US2923390A true US2923390A (en) 1960-02-02

Family

ID=27071210

Family Applications (1)

Application Number Title Priority Date Filing Date
US556676A Expired - Lifetime US2923390A (en) 1955-12-30 1955-12-30 Electrostatic clutch

Country Status (3)

Country Link
US (1) US2923390A (enrdf_load_stackoverflow)
DE (1) DE1124612B (enrdf_load_stackoverflow)
FR (1) FR1179253A (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3150678A (en) * 1960-07-11 1964-09-29 Warner Electric Brake & Clutch Device utilizing electro-viscous liquid
US3195363A (en) * 1962-02-09 1965-07-20 Litton Systems Inc Selective driving means
US3343635A (en) * 1965-03-12 1967-09-26 Gen Electric Co Ltd Electrostatic clutches
US3454137A (en) * 1966-12-23 1969-07-08 Ncr Co Lubrication device for electrostatic actuators
US3871944A (en) * 1973-06-11 1975-03-18 Minnesota Mining & Mfg Integral composite element useful in electrostatic clutch or brake devices
US11946537B2 (en) 2019-12-09 2024-04-02 American Axle & Manufacturing, Inc. Damped isolation pulley having an electro-adhesive clutch

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1255430B (de) * 1956-08-15 1967-11-30 Ibm Deutschland Elektrostatische Kupplung
DE102020203358B4 (de) 2020-03-16 2022-12-22 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein Nasslaufende, schaltbare Reibungskupplung, Kraftfahrzeug mit einer derartigen Reibungskupplung, sowie Verfahren zum Betreiben der Reibungskupplung

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1045781A (en) * 1908-06-16 1912-11-26 Nat Electric Signaling Company Wireless telegraphy.
US1533757A (en) * 1919-03-10 1925-04-14 Rahbek Knud Apparatus for changing electrical variations to mechanical
US2148482A (en) * 1934-01-10 1939-02-28 Lorenz Charles Frederick Electrical device and method of operating the same
US2417850A (en) * 1942-04-14 1947-03-25 Willis M Winslow Method and means for translating electrical impulses into mechanical force
US2568824A (en) * 1946-02-27 1951-09-25 Rahbek Knud Semiconductor unit for the utilization of electroadhesion
US2589582A (en) * 1949-08-12 1952-03-18 Strughold Peter Lubricant stick
US2686140A (en) * 1952-03-29 1954-08-10 Johns Manville Composition brake block
GB729351A (en) * 1953-01-13 1955-05-04 Glacier Co Ltd Improvements in or relating to plain bearings
US2850907A (en) * 1956-08-03 1958-09-09 Powers Samas Account Mach Ltd Motion transmitters
US2850908A (en) * 1957-03-06 1958-09-09 Powers Samas Account Mach Ltd Motion transmitters

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE412874C (de) * 1925-04-29 Erich F Huth G M B H Dr Anordnung fuer elektrostatische Relais mit Halbeleitern
DE384028C (de) * 1921-08-11 1923-11-07 Joseph Engl Dr Vorrichtung zur Umwandlung elektrischer Energie in Bewegung
DE919002C (de) * 1952-09-07 1954-10-11 Engelbert Mueller Vorrichtung zur Ausnutzung der Anziehungskraft auf Grund des Johnsen-Rahbeck-Effektes

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1045781A (en) * 1908-06-16 1912-11-26 Nat Electric Signaling Company Wireless telegraphy.
US1533757A (en) * 1919-03-10 1925-04-14 Rahbek Knud Apparatus for changing electrical variations to mechanical
US2148482A (en) * 1934-01-10 1939-02-28 Lorenz Charles Frederick Electrical device and method of operating the same
US2417850A (en) * 1942-04-14 1947-03-25 Willis M Winslow Method and means for translating electrical impulses into mechanical force
US2568824A (en) * 1946-02-27 1951-09-25 Rahbek Knud Semiconductor unit for the utilization of electroadhesion
US2589582A (en) * 1949-08-12 1952-03-18 Strughold Peter Lubricant stick
US2686140A (en) * 1952-03-29 1954-08-10 Johns Manville Composition brake block
GB729351A (en) * 1953-01-13 1955-05-04 Glacier Co Ltd Improvements in or relating to plain bearings
US2850907A (en) * 1956-08-03 1958-09-09 Powers Samas Account Mach Ltd Motion transmitters
US2850908A (en) * 1957-03-06 1958-09-09 Powers Samas Account Mach Ltd Motion transmitters

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3150678A (en) * 1960-07-11 1964-09-29 Warner Electric Brake & Clutch Device utilizing electro-viscous liquid
US3195363A (en) * 1962-02-09 1965-07-20 Litton Systems Inc Selective driving means
US3343635A (en) * 1965-03-12 1967-09-26 Gen Electric Co Ltd Electrostatic clutches
US3454137A (en) * 1966-12-23 1969-07-08 Ncr Co Lubrication device for electrostatic actuators
US3871944A (en) * 1973-06-11 1975-03-18 Minnesota Mining & Mfg Integral composite element useful in electrostatic clutch or brake devices
US11946537B2 (en) 2019-12-09 2024-04-02 American Axle & Manufacturing, Inc. Damped isolation pulley having an electro-adhesive clutch

Also Published As

Publication number Publication date
DE1124612C2 (enrdf_load_stackoverflow) 1962-09-13
DE1124612B (de) 1962-03-01
FR1179253A (fr) 1959-05-22

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