Permanent magnet braking system for drive shafts

A braking system for a rotary shaft comprising:

• a rotor mounted on said shaft and having oppositely directed rotor faces directed along said shaft;
• permanent magnets mounted on said rotor, each magnet having respective poles directed oppositely in a same orientation as said rotor faces, adjacent of said magnets having alternate poles;
• a pair of electrically conductive non-rotating plates positioned on opposite sides of said rotor and spaced from said rotor by adjustable air gaps, there being a minimum air gap dimension at which there is maximum braking of said shaft;
• and adjustment apparatus for selectively moving said plates toward and away from said rotor to vary said air gaps between said magnets and said plates when the drive shaft and rotor are rotating to thereby selectively retard rotation of the shaft, there being substantially no magnetic attraction between said magnets and said electro-conductive plates when said shaft is stationary and said air gaps are at said minimum air gap dimension.

A braking system for a wheeled vehicle comprising:

• a chassis having ground engaging drive wheels,
• a rotary shaft mounted on said chassis and coupled to said wheels;
• a magnetic disc containing equally spaced permanent magnets;
• a non-ferrous electro-conductive member separated from said disc, alternating of said magnets having poles of different polarity facing said disc;
• said disc and member being mounted on said shaft and on said chassis, respectively, such that there is an adjustable spacing between said magnets and member, and there is relative coaxial rotary motion between said disc and member when said shaft is rotating for optionally providing magnetic retarding of said shaft;
• and adjustment apparatus on said chassis for varying a position of said disc and member relative to one another along a rotary axis of said shaft between brake-on and brake-off positions such as to vary a magnitude of said magnetic retarding.

A braking system comprising:

• a frame;
• a rotary shaft mounted on said frame and coupled to a load;
• a magnetic disc containing multiple permanent magnets;
• a pair of electrically conductive members on opposite sides of said disc;
• said disc and pair being mounted, one on said shaft and the other on said frame such that there are adjustable spacings between said magnets and members, and there is relative coaxial rotary motion between said disc and pair when said shaft is rotating for optionally providing magnetic retarding of said shaft relative to said frame;
• and adjustment apparatus for varying a position of said disc and members relative to one another between brake-on and brake-off positions such as to vary a magnitude of said magnetic retarding.