US 4,228,874 A · Electromagnetic brake

Abstract

An electromagnetic brake wherein a magnetizable armature is fixed to a rotary shaft in a motor or machine and a casing for a solenoid and a permanent magnet is non-rotatably fixed to a stationary member of the motor or machine with freedom of movement in the axial direction of the armature. When the solenoid is deenergized, the magnet maintains a friction liner in the casing in frictional engagement with and brakes the armature. The electromagnetic field which is established on energization of the solenoid assists a set of helical or leaf springs to overcome the force of the magnet and to disengage the liner from the armature. The liner can be disengaged from the armature independently of the solenoid and springs by a linkage or by two bolts whose heads engage a flange of the casing and whose shanks extend through registering holes of the flange and stationary member and mesh with nuts behind the stationary member. When the linkage is actuated or the nuts are rotated in a direction to move toward the heads of the respective bolts, the casing is moved axially of and away from the armature.

Claims14

Dependent claims

An electromagnetic device for braking a first member which is rotatable with respect to a stationary second member, particularly for braking a shaft which is rotatable with respect to a stationary part of a machine, comprising a magnetizable rotary first component fixedly secured to said first member;

a second component adjacent to said first component;
and means for non-rotatably coupling said second component to said second member with freedom of movement in the axial direction of said first component, said second component comprising a permanent magnet which attracts and axially displaces said second component to and into braking engagement with said first component, and a solenoid energizable to establish an electromagnetic field tending to repel and axially displace said second component away from and out of the braking engagement with said first component.

An electromagnetic device for braking a first member which is rotatable with respect to a stationary member, particularly for braking a shaft which is rotatable with respect to a stationary part of a machine, comprising a magnetizable rotary first component fixedly secured to said first member;

a second component adjacent to said first component;
and means for non-rotatably coupling said second component to said second member with freedom of movement in the axial direction of said first component, said second component comprising a permanent magnet which attracts said second component to said first component with a first force and thereby brakes said first component and a solenoid energizable to establish an electromagnetic field tending to repel said second component from said first component;
and said coupling means including resilient means for biasing said second component away from said first component with a lesser second force.

a second component adjacent to said first component;
means for non-rotatably coupling said second component to said second member with freedom of movement in the axial direction of said first component, said second component comprising a permanent magnet which attracts said second component to and thereby brakes said first component, and a solenoid energizable to establish an electromagnetic field tending to repel said second component from said first component;
and means for disengaging said second component from said first component against the opposition of said magnet and independently of said solenoid.

Dependencies are inferred from the claim text.

Electromagnetic brake

Life of this patent

Electromagnetic brake

Life of this patent

Abstract

Claims14