US 5,172,798 A · Electrical actuation system for a drive

a housing;

first drive shaft means rotatably connected with said housing;

second drive shaft means rotatably connected with said housing;

third drive shaft means rotatably connected with said housing;

first disc stack means having a first side and a second side, said first disc stack means comprising:

a first set of annular discs connected with said first drive shaft means so as to be rotatable therewith and axially slidable with respect thereto;

and

a second set of annular discs connected with said second drive shaft means so as to be rotatable therewith and axially slidable with respect thereto, said first set of annular discs being interleaved with said second set of annular discs;

first thrust surface means connected with said second drive shaft means adjacent said first side of said first disc stack means;

second disc stack means having a first side and a second side, said second disc stack means comprising:

a third set of annular discs connected with said first drive shaft means so as to be rotatable therewith and axially slidable with respect thereto;

and

a fourth set of annular discs connected with said housing so as to be nonrotatable therewith and axially slidable with respect thereto, said set of third set of annular discs being interleaved with said fourth set of annular discs;

third disc stack means having a first side and a second side, said third disc stack means comprising:

a fifth set of annular discs connected with said first drive shaft means so as to be rotatable therewith and axially slidable with respect thereto;

and

a sixth set of annular discs connected with said third drive shaft means so as to be rotatable therewith and axially slidable with respect thereto, said fifth set of annular discs being interleaved with said sixth set of annular discs;

second thrust surface means connected with said third drive shaft means adjacent said first side of said third disc stack means;

a first electromagnetic coil assembly located within and connected to said housing, said first electromagnetic coil assembly comprising a first electromagnetic coil and a first pole piece, said first pole piece being located with respect to said first electromagnetic coil so as to be magnetizable thereby;

a first armature assembly located within said housing, said first armature assembly comprising:

first armature plate means selectively locatable within a first predetermined distance from said first pole piece;

third thrust surface means connected with said first armature plate means for selectively contacting said first side of said second disc stack means when said first armature plate means is at said first predetermined distance from said first pole piece;

first armature connection means for slidably connecting said first armature plate means with respect to said housing so that said first armature plate means may slide reciprocably between a first location whereat said first armature plate means contacts said first pole piece to a second location whereat said first armature plate means is at said first predetermined distance from said first pole piece;

first spring take-up plate means resiliently connected with said first armature plate means;

first armature spring means for resiliently connecting said first spring take-up plate means to said first armature plate means, said first armature spring means having a first end and a second end, said first end of said first armature spring means being connected with said first armature plate means, said second end of said first armature spring means being slidably connected with said first spring take-up plate means;

first armature bias means for biasing said first armature plate means away from said first pole piece and toward said second disc stack means so that said third thrust surface means selectively contacts said first side of said second disc stack means when no excitation current is supplied to said first electromagnetic coil;

first thrust plate means having fourth thrust surface means for selectively contacting the second side of said first disc stack means, said fourth thrust surface means being selectively locatable within a second predetermined distance from said second side of said first disc stack means;

and

first bearing means for connecting said first spring take-up plate means to said first thrust plate means and for permitting mutual rotation therebetween;

a second electromagnetic coil assembly located within and connected to said housing, said second electromagnetic coil assembly comprising a second electromagnetic coil and a second pole piece, said second pole piece being located with respect to said second electromagnetic coil so as to be magnetizable thereby;

and

a second armature assembly located within said housing, said second armature assembly comprising:

second armature plate means selectively locatable within a third predetermined distance from said second pole piece;

fifth thrust surface means connected with said second armature plate means for selectively contacting said second side of said second disc stack means when said second armature plate means is at said third predetermined distance from said second pole piece;

second armature connection means for slidably connecting said second armature plate means with respect to said housing so that said second armature plate means may slide reciprocably between a third location whereat said second armature plate means contacts said second pole piece to a fourth location whereat said second armature plate means is at said third predetermined distance from said second pole piece;

second spring take-up plate means resiliently connected with said second armature plate means;

second armature spring means for resiliently connecting said second spring take-up plate means to said second armature plate means, said second armature spring means having a first end and a second end, said first end of said second armature spring means being connected with said second armature plate means, said second end of said second armature spring means being slidably connected with said second spring take-up plate means;

second armature bias means for biasing said second armature plate means away from said second pole piece and toward said second disc stack means so that said fifth thrust surface selectively contacts said second side of said second disc stack means when no excitation current is supplied to said second electromagnetic coil;

second thrust plate means having a sixth thrust surface means for selectively contacting the second side of said third disc stack means, said sixth thrust surface means being selectively locatable within a fourth predetermined distance from said second side of said third disc stack means;

and

second bearing means for connecting said second spring take-up plate means to said second thrust plate means and for permitting mutual rotation therebetween;

wherein said first and second armature bias means bias respectively each of said first and second armature plate means so that said third thrust surface means and said fifth thrust surface means force respectively against said first and second sides of said second disc stack means causing said second disc stack means to be clamped between said third thrust surface means and said fifth thrust surface means thereby braking said first drive shaft means with respect to said housing;

wherein further a first excitation current supplied to said first electromagnetic coil causes said first armature plate means to be magnetically attracted to said first pole piece and as a result thereof slide on said first armature connection means toward said first pole piece until contact therewith has been made whereupon said first excitation current is reduced by a first predetermined amount which provides sufficient magnetism to keep said first armature plate means in contact with said first pole piece, and wherein said first predetermined distance is longer than said second predetermined distance;

wherein further, the movement of said first armature plate means into contact with said first pole piece causes said first armature spring means, said first spring take-up plate means, said first thrust plate means and said first bearing means to move with said first armature plate means until said fourth thrust surface means forcibly abuts said second side of said first disc stack means, wherein, said first armature spring means resiliently compresses in order to accommodate the difference between said first and second predetermined distances thereby supplying a first predetermined biasing force to said fourth thrust surface means with respect to the second side of said first disc stack means so as to clamp said first and second sets of annular discs between said first thrust surface means and said fourth thrust surface means to thereby interconnect said first drive shaft means with said second drive shaft means;

wherein further a second excitation current supplied to said second electromagnetic coil causes said second armature plate means to be magnetically attracted to said second pole piece and as a result thereof slide on said second armature connection means toward said second pole piece until contact therewith has been made whereupon said second excitation current is reduced by a second predetermined amount which provides sufficient magnetism to keep said second armature plate means in contact with said second pole piece, and wherein said third predetermined distance is longer than said fourth predetermined distance;

wherein further, the movement of said second armature plate means into contact with said second pole piece causes said second armature spring means, said second spring take-up plate means, said second thrust plate means and said second bearing means to move with said second armature plate means until said sixth thrust surface means forcibly abuts said second side of said second disc stack means, wherein, said second armature spring means resiliently compresses in order to accommodate the difference between said third and fourth predetermined distances thereby supplying a second predetermined biasing force to said sixth thrust surface means with respect to the second side of said second disc stack means so as to clamp said third and fourth sets of annular discs between said fifth thrust surface means and said sixth thrust surface means to thereby interconnect said first drive shaft means with said third drive shaft means.

Electrical actuation system for a drive

Life of this patent

Electrical actuation system for a drive

Life of this patent

Abstract

Claims42