US3494453A

US3494453A - Electromagnetic drive

Info

Publication number: US3494453A
Application number: US680894A
Authority: US
Inventors: Joseph M Sepko
Original assignee: Eaton Yale and Towne Inc
Current assignee: Signet Systems Inc
Priority date: 1967-11-06
Filing date: 1967-11-06
Publication date: 1970-02-10
Anticipated expiration: 1987-02-10
Also published as: FR1590476A; DE1806448A1

Description

Feb. 10, 1970 J. M. sEPKo ELECTROMAGNETIC DRIVE 2 Sheets-Sheet l Filed Nov. .6, 1967 v llllmT` -illlim mgglm INVENTOR. JOSEPH. M. SEP/ 0 Feb..10',1970 l J.M. smo l l3,494,453

l ELEGTROMAGNETIC DRIVE Filed Nov. e, 1967 2 sheets-sheet l2 se a/ "nl" l 04 www INVENTOR. JOSEP/l M. SEP/ 0 4 TTORNEYS United States Patent O 3,494,453 ELECTROMAGNETIC DRIVE Joseph M. Sepko, Parma, Ohio, assignor to Eaton Yale & Towne Inc., Cleveland, Ohio, a corporation of Ohio Filed Nov. 6, 1967, Ser. No. 680,894 Int. Cl. F16d 27/02; H01f 5/00 U.S. Cl. 192-84 1 Claim ABSTRACT OF THE DISCLOSURE The present invention relates to a new and improved electromagnetic drive and, particularly, to an electromagnetic clutch having driving and driven members and an electrical coil which is energizable to control the transmission of torque between the driving and driven members.

The principal object of the present invention is the provision of a new and improved electro-magnetic drive having an electrical coil which is energizable to control the transmission of torque between driving and driven members and wherein the coil is electrically grounded in a highly practical manner which is reliable in operation and simple in construction.

A further object of the present invention is the provision of a new and improved electromagnetic drive which includes an electrical coil which controls the transmission of torque between driving and driven members and is supported by .one of the driving and driven members and rotates therewith and wherein the drive is of a simpliiied construction with a minimum of electrical lead wires connected with the coil to effect the delivery of electrical energy to the coil and grounding of the coil.

A still further object of the present invention is the provision of a new and improved electromagnetic clutch which includes driving and driven members and an electrical coil for controlling the transmission of torque between the driving and driven members and wherein the electrical coil is grounded by an annular member having at least a portion thereof in electrical contact with a portion of the electrical coil and with the driven member.

Another object of the present invention is the provision of a new and improved electromagnetic cluth having a drive pulley which carries an electrical coil which extends circumferentially of the axis of rotation of the pulley and wherein an annular ring member is press fit on the pulley member and has electrical contact with at least a portion of the coil and operates to ground the coil to the pulley.

Further objects and advantages of the present invention will be apparent to those skilled in the art to which it relates from the following detailed description of a preferred embodiment thereof made with reference to the accompanying drawings forming a part of this specification and in which:

FIG. 1 is an elevational view of an electromagnetic clutch, partially in section, and which embodies the present invention;

FIG. 2 is an end view of the electromagnetic clutch of FIG. l, looking at the electromagnetic clutch of FIG. 1 along the line 2 2 thereof;

3,494,453 Patented Feb. 10, 1970 ICC FIG. 3 is a cross-sectional view of a part of the electromagnetic clutch of FIG. l;

FIG. 4 is a fragmentary sectional view on an enlarged scale .of a portion of FIG. 3; and

FIG. 5 is a sectional view taken approximately along the section line 5 5 of FIG. 3.

The present invention provides an improved electromagnetic drive of the type which includes an electrical coil for controlling the transmission of torque between driving and driven members. In particular, the present invention provides an electromagnetic clutch of a simplied construction. The present invention may be applied to electromagnetic clutches of different constructions and uses. For purposes of illustration, however, an electromagnetic clutch 10 is illustrated in the drawings.

The electromagnetic clutch 10 includes a driving member in the form of a pulley 11 and a driven member in the form of a shaft 12. Torque is transmitted from the pulley 11 to the shaft 12 through a clutch mechanism which includes a torque-transmitting armature member 13 which is drivingly connected to the shaft 12. The torque-transmitting member 13 on rotation eiects rotation of the shaft12.

The torque is transmitted from the pulley 11 to the torquetransmitting member 13 by a frictional engagement .of surface 13a on the torque-transmitting member with a surface 15a on a cover member 15 which is suitably secured by fasteners 16 to the pulley member 11.

The torque-transmitting member 13 has, as shown in FIG. l, a position out of frictional engagement with the surface 15a on the cover member 15, in which position no torque is transmitted from the pulley 11 to the shaft 12. The member 13 biased to the non-torque transmitting position, illustrated in FIG. l, by a plurality of spring members 20 which are connected to a hub portion 21` and which bias the member 13 away from engagement with the member 15. When the member 13 is out of engagement with the member 15, the pulley 11 rotates vfreely with respect to the shaft 12 and to this end, the pulley is supported by a bearing assembly, generally designated 25,

for rotation relative to the shaft 12. The drive connection between the hub portion 21 and the shaft 12 may take many forms and will not be described in detail since it is not important to the present invention.

The member 13 is moved from the position shown in FIG. 1 into drive-transmitting relationship with the member 15 upon the energization of an electrical coil 30 in a lwell known manner. The energization of the electrical coil 30 thus controls the transmission of torque from the pulley 11 to the shaft 12.

The electrical coil 30 is an annular coil member which extends circumferentially of and fully encircles the axis of rotation of the pulley member 11 and shaft 12. The coil member 30 is located in an annular recess 31 in the pulley member 11 and is encapsulated by an epoxy compound, designated at 32, which functions as an insulator between the coil 30 and body of pulley 11. The coil 30 is of the type which includes, as best shown in FIG. 5, a strip of electrical conductive material such as metal foil, which is wound around the pulley 11 providing a series of layers 32a, 32b, 32e, 32d of electrical conductive material which layers are electrically insulated from each other by insulating material between the adjacent layers and which material is designated 40. The number of layers of conductive material may vary. The thickness of each layer has been exaggerated for purposes of illustration. As an alternative, the use of strips of conductive material, the coil 30 could be comprised of coils of wire not shown and as is conventional.

Electrical energy is delivered to the coil 30 for effecting the energization thereof through an electrical conductor means 45. The electrical conductor means 45 isl connected by a suitable connector 46 to a slip ring 47. The slip ring 47 contacts an adjacent slip ring, not shown, which delivers electrical energy to the coil 30 through the slip ring 47, the connection 46 and the conductor 45 to effect energization of the coil 30. As best shown in FIG. 3, the connector 46 and the conductor 45 are also embedded in the insulating material 32. Moreover, an insulating ring 50 is supported on the pulley 11 and insulates the slip ring 47 from the body of the pulley 11.

In accordance with the present invention, the electrical coil 30 is grounded to the body of the pulley member 11. The grounding of the coil 30 is effected by a relatively simple construction which is highly reliable in operation and extremely practical in view of the simplicity of the construction.

The means for grounding the coil 30 comprises an annular ring member 60 which has a surface portion 62 which engages a portion 64 of the innermost conductive layer 32a of the electrical coil 30. The ring member 60 also has an annular inner surface 63 which engages an axially extending radially inner surface 11a of the recess 31 in the pulley member 11. The annular ring member 60 encircles the axis of rotation of the shaft, 12 and is press fit onto the pulley member 11 and particularly onto the annular surface 11a of the pulley member. The ring 60 has a greater axial extent than the coil 30 (FIG. 4) so that the ring 60 projects axially from the coil 30. This enables a radially extending stop surface 70 on the ring 60 to engage a radially extending and axially inner surface 71 of the recess 31 to position the coil 30 in a spaced apart relationship with the surface 71. The space between the coil 30 and surface 71 is filled with the epoxy compound 32 to insulate the coil 30 from the pulley 11. The ring 60 is made of a suitable electrical conductive material so as to effect grounding of the coil 30 to the body of the pulley 11. The grounding is effected due to the electrical contact between the surface 62 of the ring and the innermost layer 32a of conductive material, and the contact of the surface 63 of the ring with surface 11a of the pulley. The end of the layer 32a is suitably bonded to the ring 60 and is preferably insulated from the ring 60 except at the end portion 64 thereof, as described above.

It should be noted that the particular construction described involves the use of a single slip ring 47 and a single lead wire leading to the coil 30 from the slip ring 47. Since the grounding of the coil 30 is effected through the ring member 60, the grounding of the coil 30` requires no additional leads from the coil 30 and no additional slip rings,

y Having described my invention, I claim: ,p

1. A drive assembly comprising a driving member, a driven member, means for transmitting torque between said driving and driven members including an armature member drivingly connected to said driving member to effect rotation ofsaid driving member upon rotation thereof, said armature member having a non-torque transmitting position with respect to said driving member and a torque transmitting position with respect to said driving member in which said armature member is in frictiona] driving engagement with surface portions on said driving member, said driving member defining a generally annular recess having an axially extending radially inner sur face and a radially extending axially inner surface, an annular electrical coil carried by said driving member in said recess and energizable to effect movement of said armature member from said non-torque transmitting position to said torque transmitting position, electrical conductor means for delivering electrical energy to said electrical coil, and means for electrically grounding said elecl trical coil including an annular member electrically connected with said coil and having an inner surface disposed in engagement with said axially extending radially inner surface of said recess in said driving member to thereby provide an electrical connection between said annular member and said driving member, said annular member projecting `axially beyond said electrical coil and having a continuous annular stop surface positioned in engage ment with said radially extending axially inner surface of said recess to position said electrical coil and annular member in said recess with said electrical coil spaced apart from said axially inner surface of said recess, and epoxy compoundlling the space between said electrical coil and axially inner surface of said recess.

. References Cited UNITED STATES PATENTS 2,560,868 7/1951 Hubert. 2,973,850 3/1961 Iaeschke. 3,130,355 i 4/1964 Younger 335-299 3,214,084 10/1965 Smirl.

MARK M. NEWMAN, Primary Examiner ALLAN D. HERRMANN, Assistant Examiner U.S. C1. X.R. 335--282, 299