Controllable brake

A controllable brake, comprising:

• (a) a shaft having an axis of rotation,
• (b) a rotor manufactured from a highly magnetically permeable material having first and second rotor surfaces and an outer periphery, wherein said rotor interconnects to said shaft such that relative rotation is restrained therebetween,
• (c) a housing which radially supports said shaft, the housing being shaped with a hollow enclosed space providing a pocket radially spaced from said axis of rotation of said shaft,
• (d) a magnetically-soft yoke manufactured from a magnetically permeable material received within said pocket, said magnetically-soft yoke further having a recess therein, said recess receiving a working portion of said rotor and forming a first gap adjacent to said first rotor surface and a second gap adjacent to said second rotor surface,
• (e) a magnetically-soft medium contained within and at least partially filling said first and second gaps, and
• (f) a coil assembly adjacent to said magnetically-soft yoke for generating a changeable magnetic field therein which is directed by said magnetically-soft yoke to cause said magnetically-soft medium within said first and second gaps to change rheology thereby causing a change in torsional resistance of said controllable brake upon electrically energizing said coil assembly.

A controllable brake, comprising:

• (a) a shaft,
• (b) a rotor manufactured from a highly magnetically permeable material having first and second rotor surfaces, a working portion, and an outer periphery, said rotor interconnects to said shaft restraining relative rotation therebetween,
• (c) a housing and magnetically-soft yoke combination manufactured from a magnetically permeable powdered metal material, said housing and magnetically-soft yoke combination having a recess formed therein, said recess receiving said working portion of said rotor therein and forming a first gap adjacent to said first rotor surface, and a second gap adjacent to said second rotor surface, said housing and magnetically-soft yoke combination including a thicker section at an outer radial portion adjacent to said working portion and a thinner section at an inner radial portion adjacent to said shaft,
• (d) a magnetically-soft medium including magnetically-soft particles contained in and at least partially filling said first and second gaps, and
• (e) a coil assembly adjacent to said housing and magnetically-soft yoke combination for generating a changeable magnetic field therein which is directed to cause said magnetically-soft medium within said first and second gaps to change rheology thereby causing a change in torsional resistance of said controllable brake upon electrically energizing said coil assembly.

A controllable brake, comprising:

• (a) a shaft,
• (b) a rotor manufactured from a highly magnetically permeable material having a working portion and a rotor projection, said rotor operatively coupled to said shaft to restrain relative rotation therebetween,
• (c) a housing including a magnetically-soft yoke and a housing projection, said magnetically-soft yoke having a recess formed therein which receives said working portion of said rotor forming at least one gap,
• (d) a magnetically-soft medium contained within said at least one gap,
• (e) means for generating a magnetic field within said magnetically-soft yoke, said magnetic field being directed to cause said magnetically-soft medium to change rheology thereby causing a change in torsional resistance of said controllable brake when said means for generating said magnetic field is energized, and
• (f) least one flexible disc-like spring having a first periphery which spring loads against said housing projection and a second periphery which spring loads against said rotor projection.

A controllable brake, comprising:

• (a) a shaft,
• (b) a rotor manufactured from a highly magnetically permeable material having a working portion, said rotor operatively coupled to said shaft,
• (c) a housing including an axial pocket formed therein,
• (d) a magnetically-soft yoke including first and second yoke halves received in said axial pocket, said magnetically-soft yoke having a recess formed therein which receives said working portion of said rotor forming at least one gap,
• (e) a magnetically-soft medium contained within said at least one gap,
• (f) means for generating a magnetic field within said magnetically-soft yoke, said magnetic field being directed across said gap to cause said magnetically-soft medium to change rheology thereby causing a change in torsional resistance of said controllable brake when said means for generating said magnetic field is energized, and
• (g) axial spring bias means interactive with said housing for ensuring intimate contact between said first and second yoke halves.