US 7,265,470 B1 · Magnetic spring and actuators with multiple equilibrium positions

Abstract

Arrays of magnets configured to create linear or rotary magnetic springs with multiple equilibrium points. Some of the equilibrium points are stable, while others are unstable. No mechanical contact is required between moving and stationary elements of the magnetic springs, resulting in a virtually unlimited lifetime. The magnetic springs can be utilized in conjunction with low force electromagnetic actuators to implement multi-step linear or rotary actuators with high force, very short movement time between unstable equilibrium points, and with near-zero holding power required to maintain actuator position at any unstable equilibrium point. Specific applications that embody the present invention may include, but are not limited to, optical filters, linear valves, or any mechanism that would benefit from an efficient magnetic spring.

Claims14

Dependent claims

A rotary actuator, said rotary actuator comprising:

an arrangement of magnets including at least two arrays movable relative to one another and forming a plurality of stable equilibrium points and a plurality of unstable equilibrium points, said plurality of stable equilibrium points located about a rotational axis of said rotary actuator and said plurality of unstable equilibrium points located about said rotational axis of said rotary actuator and interspersed between said plurality of stable equilibrium points;
and
wherein said rotary actuator is capable of moving towards and past any given one of said stable equilibrium points in a springing manner via magnetic forces created by said arrangement of magnets and said rotary actuator is capable of being moved towards and held in any given one of said unstable equilibrium points in a stationary manner via low power forces created by a motive source.

A linear actuator, said linear actuator comprising:

an arrangement of magnets including at least two arrays movable relative to one another and forming a plurality of stable equilibrium points and a plurality of unstable equilibrium points, said plurality of stable equilibrium points located along a linear dimension of said linear actuator and said plurality of unstable equilibrium points located about said linear dimension of said linear actuator and interspersed between said plurality of stable equilibrium points;
and
wherein said linear actuator is capable of moving towards and past any given one of said stable equilibrium points in a springing manner via magnetic forces created by said arrangement of magnets and said linear actuator is capable of being moved towards and held in any given one of said unstable equilibrium points in a stationary manner via low power forces created by a motive source.

A rotary actuator, said rotary actuator comprising:

a plurality of stable equilibrium points formed by an arrangement of magnets, said plurality of stable equilibrium points located about a rotational axis of said rotary actuator;
a plurality of unstable equilibrium points formed by said arrangement of magnets, said plurality of unstable equilibrium points located about said rotational axis of said rotary actuator and interspersed between said plurality of stable equilibrium points;
said rotary actuator is capable of moving towards and past any given one of said stable equilibrium points in a springing manner via magnetic forces created by said arrangement of magnets and said rotary actuator is capable of being moved towards and held in any given one of said unstable equilibrium points in a stationary manner via low power forces created by a motive source;
said plurality of unstable equilibrium points includes a shallow stable equilibrium point centered within each of said plurality of unstable equilibrium points such that said rotary actuator is capable of being moved into any given one of said unstable equilibrium points via said motive source and held in a corresponding one of said shallow stable equilibrium points in a stationary manner via magnetic forces created by said arrangement of magnets;
an inner array of permanent magnets arranged circularly and having magnetic poles oriented so as to form a first Halbach array;
an outer array of permanent magnets arranged circularly and having magnetic poles oriented so as to form a second Halbach array;
said magnetic forces are created in a region between said first Halbach array and said second Halbach array, and said inner array and said outer array are arranged concentric to one another such that at least one of said inner array and said outer array are rotatable relative one to another via said magnetic forces and said low power forces;
an inner subassembly of permanent magnets arranged circularly and having magnetic poles oriented all in a first direction;
an outer subassembly of permanent magnets arranged circularly and having magnetic poles oriented all in a second direction, said second direction being identical to said first direction and arranged such that said permanent magnets of said inner subassembly are attracted to said permanent magnets of said outer subassembly;
said inner subassembly and said outer subassembly are arranged concentric to one another such that at least one of said inner subassembly and said outer subassembly are rotatable relative one to another via a shaft coupling said inner subassembly to said inner array;
and
said plurality of unstable equilibrium points includes a shallow stable equilibrium point centered within each of said plurality of unstable equilibrium points such that said rotary actuator is capable of being moved into any given one of said unstable equilibrium points via said motive source and held in a corresponding one of said shallow stable equilibrium points in a stationary manner via magnetic forces created by said arrangement of magnets.

9 more elements

A rotary actuator, said rotary actuator comprising:

a plurality of stable equilibrium points formed by an arrangement of magnets, said plurality of stable equilibrium points located about a rotational axis of said rotary actuator;
a plurality of unstable equilibrium points formed by said arrangement of magnets, said plurality of unstable equilibrium points located about said rotational axis of said rotary actuator and interspersed between said plurality of stable equilibrium points;
wherein said rotary actuator is capable of moving towards and past any given one of said stable equilibrium points in a springing manner via magnetic forces created by said arrangement of magnets and said rotary actuator is capable of being moved towards and held in any given one of said unstable equilibrium points in a stationary manner via low power forces created by a motive source;
said plurality of unstable equilibrium points includes a shallow stable equilibrium point centered within each of said plurality of unstable equilibrium points such that said rotary actuator is capable of being moved into any given one of said unstable equilibrium points via said motive source and held in a corresponding one of said shallow stable equilibrium points in a stationary manner via magnetic forces created by said arrangement of magnets;
an inner array of elongated permanent magnets arranged circularly and having magnetic poles oriented so as to form a first Halbach array;
an outer array of elongated permanent magnets arranged circularly and having magnetic poles oriented so as to form a second Halbach array;
said magnetic forces are created in a region between said first Halbach array and said second Halbach array, and said inner array and said outer array form cylinders that are arranged concentric to one another such at least one of said inner array and said outer array are rotatable relative one to another via said magnetic forces and said low power forces;
an inner subassembly of permanent magnets arranged circularly and having magnetic poles oriented all in a first direction;
an outer subassembly of permanent magnets arranged circularly and having magnetic poles oriented all in a second direction, said second direction being identical to said first direction and arranged such that said permanent magnets of said inner subassembly are attracted to said permanent magnets of said outer subassembly;
said inner subassembly and said outer subassembly are arranged concentric to one another such that that at least one of said inner subassembly and said outer subassembly are rotatable relative one to another via a shaft coupling said inner subassembly to said inner array;
and
said plurality of unstable equilibrium points includes a shallow stable equilibrium point centered within each of said plurality of unstable equilibrium points such that said rotary actuator is capable of being moved into any given one of said unstable equilibrium points via said motive source and held in a corresponding one of said shallow stable equilibrium points in a stationary manner via magnetic forces created by said arrangement of magnets.

9 more elements

Dependencies are inferred from the claim text.

Magnetic spring and actuators with multiple equilibrium positions

Life of this patent

Magnetic spring and actuators with multiple equilibrium positions

Life of this patent

Abstract

Claims14